Build header tables using metadata manager (#6222)

* Build header tables using metadata manager

* Enable MetadataManager to track use of types / methods

* Introduce `AvailableType` which replaces the CoreRT EETypeNode.
Ready-to-run doesn't emit types directly into the image but records
their use and fills a table of available types used for type resolution
between ready-to-run modules by the runtime.

* Add dependency tracking in a few existing places where references to
types are being made. In library compilation mode, the non-private types
will be rooted so they always end up in the available types table.

* Use a single NodeCache for method entrypoints instead of a separate
dictionary for ready-to-run entrypoints. To smooth over the API
differences between the base `NodeFactory` and
`ReadyToRunCodegenNodeFactory`, allow a custom GetOrAdd method that
takes a creator callback.

* Switch over `RuntimeFunctionsTable`, `TypesTable`,
`MethodEntryPointTable` to use metadata manager for the list of types /
methods to emit entries for.

src/ILCompiler.Compiler/src/Compiler/DependencyAnalysis/NodeFactory.cs

@@ -149,60 +149,18 @@ namespace ILCompiler.DependencyAnalysis
             {
                 return _cache.GetOrAdd(key, _creator);
             }
+
+            public TValue GetOrAdd(TKey key, Func<TKey, TValue> creator)
+            {
+                return _cache.GetOrAdd(key, creator);
+            }
         }
 
         private void CreateNodeCaches()
         {
-            _typeSymbols = new NodeCache<TypeDesc, IEETypeNode>((TypeDesc type) =>
-            {
-                Debug.Assert(!_compilationModuleGroup.ShouldReferenceThroughImportTable(type));
-                if (_compilationModuleGroup.ContainsType(type))
-                {
-                    if (type.IsGenericDefinition)
-                    {
-                        return new GenericDefinitionEETypeNode(this, type);
-                    }
-                    else if (type.IsCanonicalDefinitionType(CanonicalFormKind.Any))
-                    {
-                        return new CanonicalDefinitionEETypeNode(this, type);
-                    }
-                    else if (type.IsCanonicalSubtype(CanonicalFormKind.Any))
-                    {
-                        return new NecessaryCanonicalEETypeNode(this, type);
-                    }
-                    else
-                    {
-                        return new EETypeNode(this, type);
-                    }
-                }
-                else
-                {
-                    return new ExternEETypeSymbolNode(this, type);
-                }
-            });
+            _typeSymbols = new NodeCache<TypeDesc, IEETypeNode>(CreateNecessaryTypeNode);
 
-            _constructedTypeSymbols = new NodeCache<TypeDesc, IEETypeNode>((TypeDesc type) =>
-            {
-                // Canonical definition types are *not* constructed types (call NecessaryTypeSymbol to get them)
-                Debug.Assert(!type.IsCanonicalDefinitionType(CanonicalFormKind.Any));
-                Debug.Assert(!_compilationModuleGroup.ShouldReferenceThroughImportTable(type));
-
-                if (_compilationModuleGroup.ContainsType(type))
-                {
-                    if (type.IsCanonicalSubtype(CanonicalFormKind.Any))
-                    {
-                        return new CanonicalEETypeNode(this, type);
-                    }
-                    else
-                    {
-                        return new ConstructedEETypeNode(this, type);
-                    }
-                }
-                else
-                {
-                    return new ExternEETypeSymbolNode(this, type);
-                }
-            });
+            _constructedTypeSymbols = new NodeCache<TypeDesc, IEETypeNode>(CreateConstructedTypeNode);
 
             _clonedTypeSymbols = new NodeCache<TypeDesc, IEETypeNode>((TypeDesc type) =>
             {
@@ -483,6 +441,57 @@ namespace ILCompiler.DependencyAnalysis
             WindowsDebugData = new WindowsDebugDataHelper(this);
         }
 
+        protected virtual IEETypeNode CreateNecessaryTypeNode(TypeDesc type)
+        {
+            Debug.Assert(!_compilationModuleGroup.ShouldReferenceThroughImportTable(type));
+            if (_compilationModuleGroup.ContainsType(type))
+            {
+                if (type.IsGenericDefinition)
+                {
+                    return new GenericDefinitionEETypeNode(this, type);
+                }
+                else if (type.IsCanonicalDefinitionType(CanonicalFormKind.Any))
+                {
+                    return new CanonicalDefinitionEETypeNode(this, type);
+                }
+                else if (type.IsCanonicalSubtype(CanonicalFormKind.Any))
+                {
+                    return new NecessaryCanonicalEETypeNode(this, type);
+                }
+                else
+                {
+                    return new EETypeNode(this, type);
+                }
+            }
+            else
+            {
+                return new ExternEETypeSymbolNode(this, type);
+            }
+        }
+
+        protected virtual IEETypeNode CreateConstructedTypeNode(TypeDesc type)
+        {
+            // Canonical definition types are *not* constructed types (call NecessaryTypeSymbol to get them)
+            Debug.Assert(!type.IsCanonicalDefinitionType(CanonicalFormKind.Any));
+            Debug.Assert(!_compilationModuleGroup.ShouldReferenceThroughImportTable(type));
+
+            if (_compilationModuleGroup.ContainsType(type))
+            {
+                if (type.IsCanonicalSubtype(CanonicalFormKind.Any))
+                {
+                    return new CanonicalEETypeNode(this, type);
+                }
+                else
+                {
+                    return new ConstructedEETypeNode(this, type);
+                }
+            }
+            else
+            {
+                return new ExternEETypeSymbolNode(this, type);
+            }
+        }
+
         protected abstract IMethodNode CreateMethodEntrypointNode(MethodDesc method);
 
         protected abstract IMethodNode CreateUnboxingStubNode(MethodDesc method);
@@ -721,7 +730,7 @@ namespace ILCompiler.DependencyAnalysis
             return _stringAllocators.GetOrAdd(stringConstructor);
         }
 
-        private NodeCache<MethodDesc, IMethodNode> _methodEntrypoints;
+        protected NodeCache<MethodDesc, IMethodNode> _methodEntrypoints;
         private NodeCache<MethodDesc, IMethodNode> _unboxingStubs;
         private NodeCache<IMethodNode, MethodAssociatedDataNode> _methodAssociatedData;
 

src/ILCompiler.Compiler/src/Compiler/MetadataManager.cs

@@ -45,8 +45,8 @@ namespace ILCompiler
         protected readonly ManifestResourceBlockingPolicy _resourceBlockingPolicy;
 
         private List<NonGCStaticsNode> _cctorContextsGenerated = new List<NonGCStaticsNode>();
-        private HashSet<TypeDesc> _typesWithEETypesGenerated = new HashSet<TypeDesc>();
-        private HashSet<TypeDesc> _typesWithConstructedEETypesGenerated = new HashSet<TypeDesc>();
+        private readonly HashSet<TypeDesc> _typesWithEETypesGenerated = new HashSet<TypeDesc>();
+        private readonly HashSet<TypeDesc> _typesWithConstructedEETypesGenerated = new HashSet<TypeDesc>();
         private HashSet<MethodDesc> _methodsGenerated = new HashSet<MethodDesc>();
         private HashSet<GenericDictionaryNode> _genericDictionariesGenerated = new HashSet<GenericDictionaryNode>();
         private HashSet<IMethodBodyNode> _methodBodiesGenerated = new HashSet<IMethodBodyNode>();
@@ -560,7 +560,7 @@ namespace ILCompiler
             return _genericDictionariesGenerated;
         }
 
-        internal IEnumerable<MethodDesc> GetCompiledMethods()
+        public IEnumerable<MethodDesc> GetCompiledMethods()
         {
             return _methodsGenerated;
         }

src/ILCompiler.ReadyToRun/src/CodeGen/ReadyToRunObjectWriter.cs

@@ -72,14 +72,6 @@ namespace ILCompiler.DependencyAnalysis
                 _rdataSectionIndex = sectionBuilder.AddSection(".rdata", SectionCharacteristics.ContainsInitializedData | SectionCharacteristics.MemRead, 512);
                 _dataSectionIndex = sectionBuilder.AddSection(".data", SectionCharacteristics.ContainsInitializedData | SectionCharacteristics.MemWrite | SectionCharacteristics.MemRead, 512);
 
-                foreach (var depNode in _nodes)
-                {
-                    if (depNode is EETypeNode eeTypeNode)
-                    {
-                        _nodeFactory.TypesTable.Add(eeTypeNode);
-                    }
-                }
-
                 int nodeIndex = -1;
                 foreach (var depNode in _nodes)
                 {

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ExternalTypeNode.cs

@@ -0,0 +1,62 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+
+using ILCompiler.DependencyAnalysisFramework;
+
+using Internal.Text;
+using Internal.TypeSystem;
+
+namespace ILCompiler.DependencyAnalysis.ReadyToRun
+{
+    class ExternalTypeNode : DependencyNodeCore<NodeFactory>, IEETypeNode
+    {
+        private readonly TypeDesc _type;
+
+        public ExternalTypeNode(NodeFactory factory, TypeDesc type)
+        {
+            _type = type;
+
+            //
+            // This check encodes rules specific to CoreRT. Ie, no function pointer classes allowed.
+            // Eventually we will hit situations where this check fails when it shouldn't and we'll need to 
+            // split the logic. It's a good sanity check for the time being though.
+            //
+            EETypeNode.CheckCanGenerateEEType(factory, type);
+        }
+
+        public TypeDesc Type => _type;
+
+        public int Offset => 0;
+
+        public bool RepresentsIndirectionCell => false;
+
+        public int ClassCode => -1044459;
+
+        public override bool InterestingForDynamicDependencyAnalysis => false;
+
+        public override bool HasDynamicDependencies => false;
+
+        public override bool HasConditionalStaticDependencies => false;
+
+        public override bool StaticDependenciesAreComputed => true;
+
+        public void AppendMangledName(NameMangler nameMangler, Utf8StringBuilder sb)
+        {
+            sb.Append(nameMangler.GetMangledTypeName(_type));
+        }
+
+        public int CompareToImpl(ISortableNode other, CompilerComparer comparer)
+        {
+            return comparer.Compare(Type, ((AvailableType)other).Type);
+        }
+
+        public override IEnumerable<CombinedDependencyListEntry> GetConditionalStaticDependencies(NodeFactory context) => null;
+        public override IEnumerable<CombinedDependencyListEntry> SearchDynamicDependencies(List<DependencyNodeCore<NodeFactory>> markedNodes, int firstNode, NodeFactory context) => null;
+        public override IEnumerable<DependencyListEntry> GetStaticDependencies(NodeFactory context) => null;
+
+        protected override string GetName(NodeFactory factory) => $"Externally referenced type {Type.ToString()}";
+    }
+}

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/AvailableType.cs

@@ -0,0 +1,62 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Generic;
+
+using ILCompiler.DependencyAnalysisFramework;
+
+using Internal.Text;
+using Internal.TypeSystem;
+
+namespace ILCompiler.DependencyAnalysis.ReadyToRun
+{
+    public class AvailableType : DependencyNodeCore<NodeFactory>, IEETypeNode
+    {
+        private readonly TypeDesc _type;
+
+        public AvailableType(NodeFactory factory, TypeDesc type)
+        {
+            _type = type;
+
+            //
+            // This check encodes rules specific to CoreRT. Ie, no function pointer classes allowed.
+            // Eventually we will hit situations where this check fails when it shouldn't and we'll need to 
+            // split the logic. It's a good sanity check for the time being though.
+            //
+            EETypeNode.CheckCanGenerateEEType(factory, type);
+        }
+
+        public TypeDesc Type => _type;
+
+        public int Offset => 0;
+
+        public bool RepresentsIndirectionCell => false;
+
+        public int ClassCode => 345483495;
+
+        public override bool InterestingForDynamicDependencyAnalysis => false;
+
+        public override bool HasDynamicDependencies => false;
+
+        public override bool HasConditionalStaticDependencies => false;
+
+        public override bool StaticDependenciesAreComputed => true;
+
+        public void AppendMangledName(NameMangler nameMangler, Utf8StringBuilder sb)
+        {
+            sb.Append(nameMangler.GetMangledTypeName(_type));
+        }
+
+        public int CompareToImpl(ISortableNode other, CompilerComparer comparer)
+        {
+            return comparer.Compare(Type, ((AvailableType)other).Type);
+        }
+
+        public override IEnumerable<CombinedDependencyListEntry> GetConditionalStaticDependencies(NodeFactory context) => null;
+        public override IEnumerable<CombinedDependencyListEntry> SearchDynamicDependencies(List<DependencyNodeCore<NodeFactory>> markedNodes, int firstNode, NodeFactory context) => null;
+        public override IEnumerable<DependencyListEntry> GetStaticDependencies(NodeFactory context) => null;
+
+        protected override string GetName(NodeFactory factory) => $"Available type {Type.ToString()}";
+    }
+}

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/ExternalMethodImport.cs

@@ -32,6 +32,7 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
         }
 
         public MethodDesc Method => _methodDesc;
+        public MethodWithGCInfo MethodCodeNode => _localMethod;
 
         public override int ClassCode => 458823351;
 

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/MethodEntryPointTableNode.cs

@@ -66,7 +66,7 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
             }
         }
 
-        List<EntryPoint> _ridToEntryPoint;
+        private List<EntryPoint> _ridToEntryPoint;
 
         public MethodEntryPointTableNode(TargetDetails target)
             : base(target)
@@ -200,6 +200,19 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
                 return new ObjectData(Array.Empty<byte>(), Array.Empty<Relocation>(), 1, Array.Empty<ISymbolDefinitionNode>());
             }
 
+            foreach (MethodDesc method in factory.MetadataManager.GetCompiledMethods())
+            {
+                MethodWithGCInfo methodCodeNode = factory.MethodEntrypoint(method) as MethodWithGCInfo;
+                if (methodCodeNode == null)
+                {
+                    methodCodeNode = ((ExternalMethodImport)factory.MethodEntrypoint(method))?.MethodCodeNode;
+                    if (methodCodeNode == null)
+                        continue;
+                }
+
+                Add(methodCodeNode, ((ReadyToRunCodegenNodeFactory)factory).RuntimeFunctionsTable.GetIndex(methodCodeNode));
+            }
+
             NativeWriter writer = new NativeWriter();
 
             Section arraySection = writer.NewSection();

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/MethodWithGCInfo.cs

@@ -2,9 +2,10 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System;
 using System.Diagnostics;
+
 using ILCompiler.DependencyAnalysisFramework;
+
 using Internal.Text;
 using Internal.TypeSystem;
 
@@ -43,10 +44,7 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
         protected override void OnMarked(NodeFactory factory)
         {
             ReadyToRunCodegenNodeFactory r2rFactory = (ReadyToRunCodegenNodeFactory)factory;
-            // Marked method - add runtime & entry point table entry
             r2rFactory.RuntimeFunctionsGCInfo.AddEmbeddedObject(GCInfoNode);
-            int index = r2rFactory.RuntimeFunctionsTable.Add(this);
-            r2rFactory.MethodEntryPointTable.Add(this, index);
         }
 
         public override ObjectData GetData(NodeFactory factory, bool relocsOnly)

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/NewArrayFixupSignature.cs

@@ -44,5 +44,12 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
         {
             return _typeToken.CompareTo(((NewArrayFixupSignature)other)._typeToken);
         }
+
+        protected override DependencyList ComputeNonRelocationBasedDependencies(NodeFactory factory)
+        {
+            DependencyList dependencies = new DependencyList();
+            dependencies.Add(factory.NecessaryTypeSymbol(_arrayType.ElementType), "Type used as array element");
+            return dependencies;
+        }
     }
 }

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/NewObjectFixupSignature.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using ILCompiler.DependencyAnalysisFramework;
 using Internal.Text;
 using Internal.TypeSystem;
 
@@ -44,5 +45,12 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
         {
             return _typeToken.CompareTo(((NewObjectFixupSignature)other)._typeToken);
         }
+
+        protected override DependencyList ComputeNonRelocationBasedDependencies(NodeFactory factory)
+        {
+            DependencyList dependencies = new DependencyList();
+            dependencies.Add(factory.ConstructedTypeSymbol(_typeDesc), "Type constructed through new object fixup");
+            return dependencies;
+        }
     }
 }

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/RuntimeFunctionsTableNode.cs

@@ -2,20 +2,26 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using System;
 using System.Collections.Generic;
+
 using Internal.Text;
 using Internal.TypeSystem;
 
+using Debug = System.Diagnostics.Debug;
+
 namespace ILCompiler.DependencyAnalysis.ReadyToRun
 {
     public class RuntimeFunctionsTableNode : HeaderTableNode
     {
-        private readonly List<MethodWithGCInfo> _methodNodes;
+        private List<MethodWithGCInfo> _methodNodes;
+        private Dictionary<MethodWithGCInfo, int> _insertedMethodNodes;
+        private readonly NodeFactory _nodeFactory;
 
-        public RuntimeFunctionsTableNode(TargetDetails target)
-            : base(target)
+        public RuntimeFunctionsTableNode(NodeFactory nodeFactory)
+            : base(nodeFactory.Target)
         {
-            _methodNodes = new List<MethodWithGCInfo>();
+            _nodeFactory = nodeFactory;
         }
 
         public override void AppendMangledName(NameMangler nameMangler, Utf8StringBuilder sb)
@@ -24,14 +30,47 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
             sb.Append("__ReadyToRunRuntimeFunctionsTable");
         }
 
-        public int Add(MethodWithGCInfo method)
+        public int GetIndex(MethodWithGCInfo method)
         {
-            _methodNodes.Add(method);
-            return _methodNodes.Count - 1;
+#if DEBUG
+            Debug.Assert(_nodeFactory.MarkingComplete);
+            Debug.Assert(method.Marked);
+#endif
+            if (_methodNodes == null)
+                LayoutRuntimeFunctions();
+
+            return _insertedMethodNodes[method];
+        }
+
+        private void LayoutRuntimeFunctions()
+        {
+            _methodNodes = new List<MethodWithGCInfo>();
+            _insertedMethodNodes = new Dictionary<MethodWithGCInfo, int>();
+
+            foreach (MethodDesc method in _nodeFactory.MetadataManager.GetCompiledMethods())
+            {
+                MethodWithGCInfo methodCodeNode = _nodeFactory.MethodEntrypoint(method) as MethodWithGCInfo;
+                if (methodCodeNode == null)
+                {
+                    methodCodeNode = ((ExternalMethodImport)_nodeFactory.MethodEntrypoint(method))?.MethodCodeNode;
+                    if (methodCodeNode == null)
+                        continue;
+                }
+
+                _methodNodes.Add(methodCodeNode);
+                _insertedMethodNodes[methodCodeNode] = _methodNodes.Count - 1;
+            }
         }
 
         public override ObjectData GetData(NodeFactory factory, bool relocsOnly = false)
         {
+            // This node does not trigger generation of other nodes.
+            if (relocsOnly)
+                return new ObjectData(Array.Empty<byte>(), Array.Empty<Relocation>(), 1, new ISymbolDefinitionNode[] { this });
+
+            if (_methodNodes == null)
+                LayoutRuntimeFunctions();
+
             ObjectDataBuilder runtimeFunctionsBuilder = new ObjectDataBuilder(factory, relocsOnly);
 
             // Add the symbol representing this object node

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/TypeFixupSignature.cs

@@ -50,5 +50,12 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
         {
             return _typeToken.CompareTo(((TypeFixupSignature)other)._typeToken);
         }
+
+        protected override DependencyList ComputeNonRelocationBasedDependencies(NodeFactory factory)
+        {
+            DependencyList dependencies = new DependencyList();
+            dependencies.Add(factory.NecessaryTypeSymbol(_typeDesc), "Type referenced in a fixup signature");
+            return dependencies;
+        }
     }
 }

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRun/TypesTableNode.cs

@@ -17,13 +17,8 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
 {
     public class TypesTableNode : HeaderTableNode
     {
-        List<(int Rid, EETypeNode Node)> _eeTypeNodes;
-        
         public TypesTableNode(TargetDetails target)
-            : base(target)
-        {
-            _eeTypeNodes = new List<(int Rid, EETypeNode Node)>();
-        }
+            : base(target) {}
         
         public override void AppendMangledName(NameMangler nameMangler, Utf8StringBuilder sb)
         {
@@ -31,34 +26,33 @@ namespace ILCompiler.DependencyAnalysis.ReadyToRun
             sb.Append("__ReadyToRunAvailableTypesTable");
         }
 
-        public int Add(EETypeNode eeTypeNode)
-        {
-            if (eeTypeNode.Type is EcmaType ecmaType)
-            {
-                int rid = MetadataTokens.GetToken(ecmaType.Handle) & 0x00FFFFFF;
-                Debug.Assert(rid != 0);
-                int eeTypeIndex = _eeTypeNodes.Count;
-                _eeTypeNodes.Add((Rid: rid, Node: eeTypeNode));
-                return eeTypeIndex;
-            }
-            else
-            {
-                throw new NotImplementedException();
-            }
-        }
-
         public override ObjectData GetData(NodeFactory factory, bool relocsOnly = false)
         {
+            // This node does not trigger generation of other nodes.
+            if (relocsOnly)
+                return new ObjectData(Array.Empty<byte>(), Array.Empty<Relocation>(), 1, new ISymbolDefinitionNode[] { this });
+
             NativeWriter writer = new NativeWriter();
             Section section = writer.NewSection();
 
             VertexHashtable typesHashtable = new VertexHashtable();
             section.Place(typesHashtable);
 
-            foreach ((int Rid, EETypeNode Node) eeTypeNode in _eeTypeNodes)
+            foreach (TypeDesc type in ((ReadyToRunTableManager)factory.MetadataManager).GetTypesWithAvailableTypes())
             {
-                int hashCode = eeTypeNode.Node.Type.GetHashCode();
-                typesHashtable.Append(unchecked((uint)hashCode), section.Place(new UnsignedConstant((uint)eeTypeNode.Rid << 1)));
+                int rid = 0;
+                if (type is EcmaType ecmaType)
+                {
+                    rid = MetadataTokens.GetToken(ecmaType.Handle) & 0x00FFFFFF;
+                    Debug.Assert(rid != 0);
+                }
+                else
+                {
+                    throw new NotImplementedException();
+                }
+
+                int hashCode = type.GetHashCode();
+                typesHashtable.Append(unchecked((uint)hashCode), section.Place(new UnsignedConstant((uint)rid << 1)));
             }
 
             MemoryStream writerContent = new MemoryStream();

src/ILCompiler.ReadyToRun/src/Compiler/DependencyAnalysis/ReadyToRunCodegenNodeFactory.cs

@@ -74,17 +74,12 @@ namespace ILCompiler.DependencyAnalysis
 
         public ImportSectionNode PrecodeImports;
 
-        Dictionary<MethodDesc, IMethodNode> _methodMap = new Dictionary<MethodDesc, IMethodNode>();
-
         public IMethodNode MethodEntrypoint(MethodDesc method, ModuleToken token, bool isUnboxingStub = false)
         {
-            IMethodNode methodNode;
-            if (!_methodMap.TryGetValue(method, out methodNode))
+            return _methodEntrypoints.GetOrAdd(method, (m) => 
             {
-                methodNode = CreateMethodEntrypointNode(method, token, isUnboxingStub);
-                _methodMap.Add(method, methodNode);
-            }
-            return methodNode;
+                return CreateMethodEntrypointNode(method, token, isUnboxingStub);
+            });
         }
 
         private IMethodNode CreateMethodEntrypointNode(MethodDesc method, ModuleToken token, bool isUnboxingStub = false)
@@ -589,7 +584,7 @@ namespace ILCompiler.DependencyAnalysis
             var compilerIdentifierNode = new CompilerIdentifierNode(Target);
             Header.Add(Internal.Runtime.ReadyToRunSectionType.CompilerIdentifier, compilerIdentifierNode, compilerIdentifierNode);
 
-            RuntimeFunctionsTable = new RuntimeFunctionsTableNode(Target);
+            RuntimeFunctionsTable = new RuntimeFunctionsTableNode(this);
             Header.Add(Internal.Runtime.ReadyToRunSectionType.RuntimeFunctions, RuntimeFunctionsTable, RuntimeFunctionsTable);
 
             RuntimeFunctionsGCInfo = new RuntimeFunctionsGCInfoNode();
@@ -660,6 +655,8 @@ namespace ILCompiler.DependencyAnalysis
             graph.AddRoot(PrecodeImports, "Precode imports are always generated");
             graph.AddRoot(StringImports, "String imports are always generated");
             graph.AddRoot(Header, "ReadyToRunHeader is always generated");
+
+            MetadataManager.AttachToDependencyGraph(graph);
         }
 
         public IMethodNode ImportedMethodNode(MethodDesc method, bool unboxingStub, ModuleToken token, MethodWithGCInfo localMethod)
@@ -717,6 +714,33 @@ namespace ILCompiler.DependencyAnalysis
             return MethodEntrypoint(method, token, isUnboxingStub);
         }
 
+        protected override IEETypeNode CreateNecessaryTypeNode(TypeDesc type)
+        {
+            if (CompilationModuleGroup.ContainsType(type))
+            {
+                return new AvailableType(this, type);
+            }
+            else
+            {
+                return new ExternalTypeNode(this, type);
+            }
+        }
+
+        protected override IEETypeNode CreateConstructedTypeNode(TypeDesc type)
+        {
+            // Canonical definition types are *not* constructed types (call NecessaryTypeSymbol to get them)
+            Debug.Assert(!type.IsCanonicalDefinitionType(CanonicalFormKind.Any));
+            
+            if (CompilationModuleGroup.ContainsType(type))
+            {
+                return new AvailableType(this, type);
+            }
+            else
+            {
+                return new ExternalTypeNode(this, type);
+            }
+        }
+
         protected override IMethodNode CreateMethodEntrypointNode(MethodDesc method)
         {
             if (!CompilationModuleGroup.ContainsMethodBody(method, unboxingStub: false))

src/ILCompiler.ReadyToRun/src/Compiler/ReadyToRunTableManager.cs

@@ -0,0 +1,57 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+
+using ILCompiler.DependencyAnalysis;
+using ILCompiler.DependencyAnalysis.ReadyToRun;
+using ILCompiler.DependencyAnalysisFramework;
+
+using Internal.TypeSystem;
+
+using Debug = System.Diagnostics.Debug;
+
+namespace ILCompiler
+{
+    public class ReadyToRunTableManager : MetadataManager
+    {
+        private readonly HashSet<TypeDesc> _typesWithAvailableTypesGenerated = new HashSet<TypeDesc>();
+
+        public ReadyToRunTableManager(CompilerTypeSystemContext typeSystemContext)
+            : base(typeSystemContext, new NoMetadataBlockingPolicy(), new NoManifestResourceBlockingPolicy()) {}
+
+        public override void AddToReadyToRunHeader(ReadyToRunHeaderNode header, NodeFactory nodeFactory, ExternalReferencesTableNode commonFixupsTableNode)
+        {
+            // We don't attach any metadata blobs.
+        }
+
+        protected override void Graph_NewMarkedNode(DependencyNodeCore<NodeFactory> obj)
+        {
+            base.Graph_NewMarkedNode(obj);
+            
+            var eetypeNode = obj as AvailableType;
+            if (eetypeNode != null)
+            {
+                _typesWithAvailableTypesGenerated.Add(eetypeNode.Type);
+                return;
+            }
+        }
+
+        public IEnumerable<TypeDesc> GetTypesWithAvailableTypes()
+        {
+            return _typesWithAvailableTypesGenerated;
+        }
+
+        public override MethodDesc GetCanonicalReflectionInvokeStub(MethodDesc method) => throw new NotImplementedException();
+        public override IEnumerable<ModuleDesc> GetCompilationModulesWithMetadata() => throw new NotImplementedException();
+        public override bool HasReflectionInvokeStubForInvokableMethod(MethodDesc method) => throw new NotImplementedException();
+        public override bool WillUseMetadataTokenToReferenceField(FieldDesc field) => throw new NotImplementedException();
+        public override bool WillUseMetadataTokenToReferenceMethod(MethodDesc method) => throw new NotImplementedException();
+        protected override void ComputeMetadata(NodeFactory factory, out byte[] metadataBlob, out List<MetadataMapping<MetadataType>> typeMappings, out List<MetadataMapping<MethodDesc>> methodMappings, out List<MetadataMapping<FieldDesc>> fieldMappings, out List<MetadataMapping<MethodDesc>> stackTraceMapping) => throw new NotImplementedException();
+        protected override MetadataCategory GetMetadataCategory(MethodDesc method) => throw new NotImplementedException();
+        protected override MetadataCategory GetMetadataCategory(TypeDesc type) => throw new NotImplementedException();
+        protected override MetadataCategory GetMetadataCategory(FieldDesc field) => throw new NotImplementedException();
+    }
+}

src/ILCompiler.ReadyToRun/src/ILCompiler.ReadyToRun.csproj

@@ -28,7 +28,9 @@
   
   <ItemGroup>
     <Compile Include="CodeGen\ReadyToRunObjectWriter.cs" />
+    <Compile Include="Compiler\DependencyAnalysis\ExternalTypeNode.cs" />
     <Compile Include="Compiler\DependencyAnalysis\ReadyToRunCodegenNodeFactory.cs" />
+    <Compile Include="Compiler\DependencyAnalysis\ReadyToRun\AvailableType.cs" />
     <Compile Include="Compiler\DependencyAnalysis\ReadyToRun\ByteArrayComparer.cs" />
     <Compile Include="Compiler\DependencyAnalysis\ReadyToRun\CompilerIdentifierNode.cs" />
     <Compile Include="Compiler\DependencyAnalysis\ReadyToRun\DelayLoadHelperImport.cs" />
@@ -72,6 +74,7 @@
     <Compile Include="Compiler\ReadyToRunMetadataFieldLayoutAlgorithm.cs" />
     <Compile Include="Compiler\ReadyToRunNodeMangler.cs" />
     <Compile Include="Compiler\ReadyToRunSingleAssemblyCompilationModuleGroup.cs" />
+    <Compile Include="Compiler\ReadyToRunTableManager.cs" />
     <Compile Include="JitInterface\CorInfoImpl.ReadyToRun.cs" />
     <Compile Include="ObjectWriter\SectionBuilder.cs" />
     <Compile Include="ObjectWriter\R2RPEBuilder.cs" />

src/ILCompiler/src/Program.cs

@@ -491,7 +491,16 @@ namespace ILCompiler
 
             bool supportsReflection = !_isReadyToRunCodeGen && !_isWasmCodegen && !_isCppCodegen && _systemModuleName == DefaultSystemModule;
 
-            MetadataManager compilationMetadataManager = supportsReflection ? metadataManager : (MetadataManager)new EmptyMetadataManager(typeSystemContext);
+            MetadataManager compilationMetadataManager;
+            if (_isReadyToRunCodeGen)
+            {
+                compilationMetadataManager = new ReadyToRunTableManager(typeSystemContext);
+            }
+            else
+            {
+                compilationMetadataManager = supportsReflection ? metadataManager : (MetadataManager)new EmptyMetadataManager(typeSystemContext);
+            }
+            
             ILScanResults scanResults = null;
             if (useScanner)
             {

tests/src/Simple/ReadyToRunUnit/Program.cs

@@ -261,6 +261,25 @@ internal class Program
         return true;
     }
     
+    private static bool CreateLocalClassInstance()
+    {
+        var testClass = new TestClass(1234);
+        Console.WriteLine("Successfully constructed TestClass");
+        return testClass.A == 1234;
+    }
+
+    private class TestClass
+    {
+        private int _a;
+
+        public TestClass(int a)
+        {
+            _a = a;
+        }
+
+        public int A => _a;
+    }
+
     public static int Main(string[] args)
     {
         if (args.Length > 0)
@@ -290,6 +309,8 @@ internal class Program
         RunTest("ManipulateListOfString", ManipulateListOfString());
 
         RunTest("EmptyArray", EmptyArray());
+        RunTest("CreateLocalClassInstance", CreateLocalClassInstance());
+        
         // TODO: RunTest("EnumerateEmptyArray", EnumerateEmptyArray());
 
         Console.WriteLine($@"{_passedTests.Count} tests pass:");