From 0fb4c666804ae443b6866b5fde5f3c1159c9a417 Mon Sep 17 00:00:00 2001
From: Max Charlamb <44248479+max-charlamb@users.noreply.github.com>
Date: Fri, 24 Oct 2025 10:03:25 -0400
Subject: [PATCH] support dynamic contracts

---
 .../ContractRegistry.cs                       |  4 +++-
 .../IContractFactory.cs                       |  1 +
 .../CachingContractRegistry.cs                | 21 +++++++++++++++----
 .../ContractDescriptorTarget.cs               |  3 ++-
 .../Legacy/SOSDacImpl.cs                      |  2 +-
 5 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/ContractRegistry.cs b/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/ContractRegistry.cs
index 85f4f954404536..0516c0dac2c964 100644
--- a/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/ContractRegistry.cs
+++ b/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/ContractRegistry.cs
@@ -89,5 +89,7 @@ public abstract class ContractRegistry
     /// <summary>
     /// Gets an instance of the SignatureDecoder contract for the target.
     /// </summary>
-    public abstract ISignatureDecoder SignatureDecoder { get; }
+    // public abstract ISignatureDecoder SignatureDecoder { get; }
+
+    public abstract TContract GetContract<TContract>() where TContract : IContract;
 }
diff --git a/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/IContractFactory.cs b/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/IContractFactory.cs
index ca19d7ed3d05fb..2973c86784f554 100644
--- a/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/IContractFactory.cs
+++ b/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Abstractions/IContractFactory.cs
@@ -8,4 +8,5 @@ namespace Microsoft.Diagnostics.DataContractReader;
 public interface IContractFactory<out TContract> where TContract : Contracts.IContract
 {
     TContract CreateContract(Target target, int version);
+    Type ContractType => typeof(TContract);
 }
diff --git a/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader/CachingContractRegistry.cs b/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader/CachingContractRegistry.cs
index 0afe774efde541..210e12c8c356b0 100644
--- a/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader/CachingContractRegistry.cs
+++ b/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader/CachingContractRegistry.cs
@@ -20,7 +20,11 @@ internal sealed class CachingContractRegistry : ContractRegistry
     private readonly Target _target;
     private readonly TryGetContractVersionDelegate _tryGetContractVersion;
 
-    public CachingContractRegistry(Target target, TryGetContractVersionDelegate tryGetContractVersion, Action<Dictionary<Type, IContractFactory<IContract>>>? configureFactories = null)
+    public CachingContractRegistry(
+        Target target,
+        TryGetContractVersionDelegate tryGetContractVersion,
+        IEnumerable<IContractFactory<IContract>>? additionalFactories = null,
+        Action<Dictionary<Type, IContractFactory<IContract>>>? configureFactories = null)
     {
         _target = target;
         _tryGetContractVersion = tryGetContractVersion;
@@ -45,8 +49,17 @@ public CachingContractRegistry(Target target, TryGetContractVersionDelegate tryG
             [typeof(ISHash)] = new SHashFactory(),
             [typeof(IGC)] = new GCFactory(),
             [typeof(INotifications)] = new NotificationsFactory(),
-            [typeof(ISignatureDecoder)] = new SignatureDecoderFactory(),
+            // [typeof(ISignatureDecoder)] = new SignatureDecoderFactory(),
         };
+
+        if (additionalFactories != null)
+        {
+            foreach (IContractFactory<IContract> factory in additionalFactories)
+            {
+                _factories[factory.ContractType] = factory;
+            }
+        }
+
         configureFactories?.Invoke(_factories);
     }
 
@@ -69,9 +82,9 @@ public CachingContractRegistry(Target target, TryGetContractVersionDelegate tryG
     public override ISHash SHash => GetContract<ISHash>();
     public override IGC GC => GetContract<IGC>();
     public override INotifications Notifications => GetContract<INotifications>();
-    public override ISignatureDecoder SignatureDecoder => GetContract<ISignatureDecoder>();
+    // public override ISignatureDecoder SignatureDecoder => GetContract<ISignatureDecoder>();
 
-    private TContract GetContract<TContract>() where TContract : IContract
+    public override TContract GetContract<TContract>()
     {
         if (_contracts.TryGetValue(typeof(TContract), out IContract? contractMaybe))
             return (TContract)contractMaybe;
diff --git a/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader/ContractDescriptorTarget.cs b/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader/ContractDescriptorTarget.cs
index bec5c1cb7dc3f1..62255ee52a4ea5 100644
--- a/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader/ContractDescriptorTarget.cs
+++ b/src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader/ContractDescriptorTarget.cs
@@ -8,6 +8,7 @@
 using System.Numerics;
 using System.Runtime.CompilerServices;
 using System.Text;
+using Microsoft.Diagnostics.DataContractReader.Contracts;
 using Microsoft.Diagnostics.DataContractReader.Data;
 
 namespace Microsoft.Diagnostics.DataContractReader;
@@ -108,7 +109,7 @@ public static ContractDescriptorTarget Create(
 
     private ContractDescriptorTarget(Descriptor[] descriptors, DataTargetDelegates dataTargetDelegates)
     {
-        Contracts = new CachingContractRegistry(this, this.TryGetContractVersion);
+        Contracts = new CachingContractRegistry(this, this.TryGetContractVersion, [new SignatureDecoderFactory()]);
         ProcessedData = new DataCache(this);
         _config = descriptors[0].Config;
         _dataTargetDelegates = dataTargetDelegates;
diff --git a/src/native/managed/cdac/mscordaccore_universal/Legacy/SOSDacImpl.cs b/src/native/managed/cdac/mscordaccore_universal/Legacy/SOSDacImpl.cs
index 9061601fd126c6..8b7ee7a40933f7 100644
--- a/src/native/managed/cdac/mscordaccore_universal/Legacy/SOSDacImpl.cs
+++ b/src/native/managed/cdac/mscordaccore_universal/Legacy/SOSDacImpl.cs
@@ -765,7 +765,7 @@ int ISOSDacInterface.GetFieldDescData(ClrDataAddress fieldDesc, DacpFieldDescDat
 
             IRuntimeTypeSystem rtsContract = _target.Contracts.RuntimeTypeSystem;
             IEcmaMetadata ecmaMetadataContract = _target.Contracts.EcmaMetadata;
-            ISignatureDecoder signatureDecoder = _target.Contracts.SignatureDecoder;
+            ISignatureDecoder signatureDecoder = _target.Contracts.GetContract<ISignatureDecoder>();
 
             TargetPointer fieldDescTargetPtr = fieldDesc.ToTargetPointer(_target);
             CorElementType fieldDescType = rtsContract.GetFieldDescType(fieldDescTargetPtr);