FuncEval #1 - Introduce a DAC accessible global variable in the runti…

…me to store the address of the method to be called in a FuncEval.

[tfs-changeset: 1645909]

src/Native/Runtime/CMakeLists.txt

@@ -4,6 +4,7 @@ set(COMMON_RUNTIME_SOURCES
     CachedInterfaceDispatch.cpp
     Crst.cpp
     DebugEventSource.cpp
+    DebugFuncEval.cpp
     dllmain.cpp
     eetype.cpp
     EHHelpers.cpp

src/Native/Runtime/DebugFuncEval.cpp

@@ -0,0 +1,18 @@
+// 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.
+
+#include "common.h"
+#include "CommonTypes.h"
+#include "DebugFuncEval.h"
+
+GVAL_IMPL_INIT(UInt64, g_FuncEvalTarget, 0);
+
+#ifndef DACCESS_COMPILE
+
+void* DebugFuncEval::GetFuncEvalTarget()
+{
+    return (void*)g_FuncEvalTarget;
+}
+
+#endif //!DACCESS_COMPILE

src/Native/Runtime/DebugFuncEval.h

@@ -0,0 +1,36 @@
+// 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.
+// -----------------------------------------------------------------------------------------------------------
+// Support for evaluating expression in the debuggee during debugging
+// -----------------------------------------------------------------------------------------------------------
+
+#ifndef __DEBUG_FUNC_EVAL_H__
+#define __DEBUG_FUNC_EVAL_H__
+
+#include "common.h"
+#include "CommonTypes.h"
+#include "CommonMacros.h"
+#include "daccess.h"
+
+#ifndef DACCESS_COMPILE
+
+class DebugFuncEval
+{
+public:
+    /// <summary>
+    /// Retrieve the global FuncEval target address
+    /// </summary>
+    /// <remarks>
+    /// During debugging, if a FuncEval is requested, 
+    /// The func eval infrastructure needs to know which function to call, and
+    /// It will call this API to obtain the target address.
+    /// By the time, the value should have been set through the UpdateFuncEvalTarget() method 
+    /// on the ISosRedhawk7 interface.
+    /// </remarks>
+    static void* GetFuncEvalTarget();
+};
+
+#endif //!DACCESS_COMPILE
+
+#endif // __DEBUG_FUNC_EVAL_H__