Invoke debugger function evaluations through managed UCO

src/coreclr/System.Private.CoreLib/src/System/Diagnostics/Debugger.cs

@@ -4,6 +4,7 @@
 // The Debugger class is a part of the System.Diagnostics package
 // and is used for communicating with a debugger.
 
+using System.Reflection;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
@@ -93,5 +94,22 @@ static void NotifyOfCrossThreadDependencySlow()
         [DebuggerStepThrough]
         [DebuggerHidden]
         internal static void UserBreakpoint() => Break();
+
+        [UnmanagedCallersOnly]
+        [StackTraceHidden]
+        [DebuggerHidden]
+        internal static unsafe void InvokeFunction(IntPtr methodHandle, IntPtr declaringTypeHandle, IntPtr* storage)
+        {
+            RuntimeType declaringType = RuntimeTypeHandle.GetRuntimeTypeFromHandle(declaringTypeHandle);
+            MethodBase? method = RuntimeType.GetMethodBase(declaringType, new RuntimeMethodHandleInternal(methodHandle));
+            Debug.Assert(method is RuntimeMethodInfo or RuntimeConstructorInfo);
+
+            MethodBaseInvoker invoker = method is RuntimeMethodInfo methodInfo
+                ? methodInfo.Invoker
+                : ((RuntimeConstructorInfo)method!).Invoker;
+
+            // Exceptions must reach the native func-eval handler without introducing a managed catch site.
+            invoker.InvokeForDebugger(storage);
+        }
     }
 }

src/coreclr/System.Private.CoreLib/src/System/Reflection/MethodBaseInvoker.CoreCLR.cs

@@ -1,13 +1,16 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System.Diagnostics;
 using System.Reflection.Emit;
+using System.Threading;
 
 namespace System.Reflection
 {
     internal partial class MethodBaseInvoker
     {
         private IntrinsicInvokeHelper.InvokeState _invokeState;
+        private InvokerEmitUtil.InvokeFunc_Debugger? _invokeFunc_Debugger;
 
         internal unsafe MethodBaseInvoker(RuntimeMethodInfo method) : this(method, method.Signature.Arguments)
         {
@@ -39,5 +42,22 @@ internal unsafe MethodBaseInvoker(DynamicMethod method, Signature signature) : t
 
             return _invokeFunc_RefArgs!(obj, args);
         }
+
+        [StackTraceHidden]
+        [DebuggerHidden]
+        internal unsafe void InvokeForDebugger(IntPtr* storage)
+        {
+            InvokerEmitUtil.InvokeFunc_Debugger? invoke = Volatile.Read(ref _invokeFunc_Debugger);
+            if (invoke is null)
+            {
+                using (AssemblyBuilder.ForceAllowDynamicCode())
+                {
+                    invoke = InvokerEmitUtil.CreateInvokeDelegate_Debugger(_method);
+                }
+                invoke = Interlocked.CompareExchange(ref _invokeFunc_Debugger, invoke, null) ?? invoke;
+            }
+
+            invoke(storage);
+        }
     }
 }

src/coreclr/System.Private.CoreLib/src/System/Reflection/RuntimeMethodInfo.CoreCLR.cs

@@ -40,7 +40,7 @@ internal InvocationFlags InvocationFlags
             }
         }
 
-        private MethodBaseInvoker Invoker
+        internal MethodBaseInvoker Invoker
         {
             [MethodImpl(MethodImplOptions.AggressiveInlining)]
             get

src/coreclr/debug/ee/debugger.cpp

@@ -1279,7 +1279,6 @@ DebuggerEval::DebuggerEval(CONTEXT * pContext, DebuggerIPCE_FuncEvalInfo * pEval
     m_pAssembly = pEvalInfo->vmAssembly.GetRawPtr();
     m_funcEvalKey = pEvalInfo->funcEvalKey;
     m_argCount = pEvalInfo->argCount;
-    m_targetCodeAddr = (TADDR)NULL;
     m_stringSize = pEvalInfo->stringSize;
     m_arrayRank = pEvalInfo->arrayRank;
     m_genericArgsCount = pEvalInfo->genericArgsCount;
@@ -14335,7 +14334,7 @@ Debugger::FuncEvalAbort(
     CONTRACTL
     {
         THROWS;
-        GC_NOTRIGGER;
+        if (g_pEEInterface->GetThread() != nullptr) { GC_TRIGGERS; } else { GC_NOTRIGGER; }
     }
     CONTRACTL_END;
 
@@ -14398,7 +14397,7 @@ Debugger::FuncEvalRudeAbort(
     CONTRACTL
     {
         THROWS;
-        GC_NOTRIGGER;
+        if (g_pEEInterface->GetThread() != nullptr) { GC_TRIGGERS; } else { GC_NOTRIGGER; }
     }
     CONTRACTL_END;
 

src/coreclr/debug/ee/debugger.h

@@ -3391,7 +3391,6 @@ class DebuggerEval
     SIZE_T                             m_stringSize;
     BYTE                              *m_argData;
     MethodDesc                        *m_md;
-    PCODE                              m_targetCodeAddr;
     ARG_SLOT                           m_result[NUMBER_RETURNVALUE_SLOTS];
     TypeHandle                         m_resultType;
     SIZE_T                             m_arrayRank;