From e61d726979b3e709a3c5f23b6461913e8fe3eb53 Mon Sep 17 00:00:00 2001
From: SingleAccretion <AccretionMail@yandex.ru>
Date: Sun, 21 Jan 2024 23:01:38 +0300
Subject: [PATCH] Enable writeable data for WASM

This is going upstream.
---
 .../Common/src/Internal/Runtime/MethodTable.cs      |  5 ++---
 .../Compiler/DependencyAnalysis/EETypeNode.cs       | 13 +++++++++----
 .../aot/ILCompiler.LLVM/CodeGen/LLVMObjectWriter.cs | 12 ++++++++++++
 .../Preinitialization/Preinitialization.cs          |  2 --
 4 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/src/coreclr/nativeaot/Common/src/Internal/Runtime/MethodTable.cs b/src/coreclr/nativeaot/Common/src/Internal/Runtime/MethodTable.cs
index 106b5d1c2242..e24feb5536de 100644
--- a/src/coreclr/nativeaot/Common/src/Internal/Runtime/MethodTable.cs
+++ b/src/coreclr/nativeaot/Common/src/Internal/Runtime/MethodTable.cs
@@ -190,8 +190,7 @@ internal static bool SupportsWritableData
         {
             get
             {
-                // For now just key this off of SupportsRelativePointer to avoid this on both CppCodegen and WASM.
-                return SupportsRelativePointers;
+                return true;
             }
         }
 
@@ -1184,7 +1183,7 @@ internal void* WritableData
 
                 uint offset = GetFieldOffset(EETypeField.ETF_WritableData);
 
-                if (!IsDynamicType)
+                if (!IsDynamicType && SupportsRelativePointers)
                     return (void*)GetField<RelativePointer>(offset).Value;
                 else
                     return (void*)GetField<Pointer>(offset).Value;
diff --git a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs
index e136b1057cf1..48ee9cbc18a2 100644
--- a/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs
+++ b/src/coreclr/tools/aot/ILCompiler.Compiler/Compiler/DependencyAnalysis/EETypeNode.cs
@@ -103,8 +103,7 @@ public EETypeNode(NodeFactory factory, TypeDesc type)
             factory.TypeSystemContext.EnsureLoadableType(type);
         }
 
-        public static bool SupportsWritableData(TargetDetails target)
-            => target.SupportsRelativePointers;
+        public static bool SupportsWritableData(TargetDetails target) => true;
 
         public static bool SupportsFrozenRuntimeTypeInstances(TargetDetails target)
             => SupportsWritableData(target);
@@ -1125,11 +1124,17 @@ protected void OutputWritableData(NodeFactory factory, ref ObjectDataBuilder obj
         {
             if (_writableDataNode != null)
             {
-                objData.EmitReloc(_writableDataNode, RelocType.IMAGE_REL_BASED_RELPTR32);
+                if (factory.Target.SupportsRelativePointers)
+                    objData.EmitReloc(_writableDataNode, RelocType.IMAGE_REL_BASED_RELPTR32);
+                else
+                    objData.EmitPointerReloc(_writableDataNode);
             }
             else if (SupportsWritableData(factory.Target))
             {
-                objData.EmitInt(0);
+                if (factory.Target.SupportsRelativePointers)
+                    objData.EmitInt(0);
+                else
+                    objData.EmitZeroPointer();
             }
         }
 
diff --git a/src/coreclr/tools/aot/ILCompiler.LLVM/CodeGen/LLVMObjectWriter.cs b/src/coreclr/tools/aot/ILCompiler.LLVM/CodeGen/LLVMObjectWriter.cs
index c145c72524e5..2653826f475e 100644
--- a/src/coreclr/tools/aot/ILCompiler.LLVM/CodeGen/LLVMObjectWriter.cs
+++ b/src/coreclr/tools/aot/ILCompiler.LLVM/CodeGen/LLVMObjectWriter.cs
@@ -248,6 +248,8 @@ private void EmitObjectNode(ObjectNode node, ObjectData nodeContents)
                 if (nextRelocValid)
                 {
                     Relocation reloc = nodeContents.Relocs[relocIndex];
+                    Debug.Assert(IsSupportedRelocType(node, reloc.RelocType), $"{reloc.RelocType} in {node} not supported");
+
                     long delta;
                     fixed (void* location = &data[reloc.Offset])
                     {
@@ -313,6 +315,16 @@ private void EmitObjectNode(ObjectNode node, ObjectData nodeContents)
             }
         }
 
+        private static bool IsSupportedRelocType(ObjectNode node, RelocType type)
+        {
+            if (node is StackTraceMethodMappingNode)
+            {
+                // Stack trace metadata uses relative pointers, but is currently unused.
+                return true;
+            }
+            return type is RelocType.IMAGE_REL_BASED_HIGHLOW;
+        }
+
         private void EmitSymbolDef(LLVMValueRef baseSymbol, ReadOnlySpan<byte> symbolIdentifier, int offsetFromBaseSymbol)
         {
             LLVMValueRef symbolAddress = baseSymbol;
diff --git a/src/tests/nativeaot/SmokeTests/Preinitialization/Preinitialization.cs b/src/tests/nativeaot/SmokeTests/Preinitialization/Preinitialization.cs
index 62c6f5211a94..5252e1f2d58c 100644
--- a/src/tests/nativeaot/SmokeTests/Preinitialization/Preinitialization.cs
+++ b/src/tests/nativeaot/SmokeTests/Preinitialization/Preinitialization.cs
@@ -55,9 +55,7 @@ private static int Main()
         TestReadOnlySpan.Run();
         TestStaticInterfaceMethod.Run();
         TestConstrainedCall.Run();
-#if !CODEGEN_WASM
         TestTypeHandles.Run();
-#endif
         TestIsValueType.Run();
         TestIndirectLoads.Run();
         TestInitBlock.Run();