Alter CCW wrapping semantics (#23709)

* Update CCW semantics to not unwrap when a managed COM server was activated
  from a managed COM client. This is a functional change from .NET Framework.

* Add support for CoreShim to "attach" to the existing CLR instance when
 running from a CoreRun scenario.

* Add testing for NET COM client activating a NET COM server

3 files changed, 54 insertions, 1 deletions

diff --git a/src/coreclr/hosts/corerun/corerun.cpp b/src/coreclr/hosts/corerun/corerun.cpp
index 42aa3009ea..e1864c81f7 100644
--- a/src/coreclr/hosts/corerun/corerun.cpp
+++ b/src/coreclr/hosts/corerun/corerun.cpp
@@ -423,6 +423,41 @@ private:
     ULONG_PTR _actCookie;
 };
 
+class ClrInstanceDetails
+{
+    static void * _currentClrInstance;
+    static unsigned int _currentAppDomainId;
+
+public: // static
+    static HRESULT GetDetails(void **clrInstance, unsigned int *appDomainId)
+    {
+        *clrInstance = _currentClrInstance;
+        *appDomainId = _currentAppDomainId;
+        return S_OK;
+    }
+
+public:
+    ClrInstanceDetails(void *clrInstance, unsigned int appDomainId)
+    {
+        _currentClrInstance = clrInstance;
+        _currentAppDomainId = appDomainId;
+    }
+
+    ~ClrInstanceDetails()
+    {
+        _currentClrInstance = nullptr;
+        _currentAppDomainId = 0;
+    }
+};
+
+void * ClrInstanceDetails::_currentClrInstance;
+unsigned int ClrInstanceDetails::_currentAppDomainId;
+
+extern "C" __declspec(dllexport) HRESULT __cdecl GetCurrentClrDetails(void **clrInstance, unsigned int *appDomainId)
+{
+    return ClrInstanceDetails::GetDetails(clrInstance, appDomainId);
+}
+
 bool TryLoadHostPolicy(StackSString& hostPolicyPath)
 {
     const WCHAR *hostpolicyName = W("hostpolicy.dll");
@@ -666,6 +701,7 @@ bool TryRun(const int argc, const wchar_t* argv[], Logger &log, const bool verbo
 
     {
         ActivationContext cxt{ log, managedAssemblyFullName.GetUnicode() };
+        ClrInstanceDetails current{ host, domainId };
 
         hr = host->ExecuteAssembly(domainId, managedAssemblyFullName, argc - 1, (argc - 1) ? &(argv[1]) : NULL, &exitCode);
         if (FAILED(hr))
diff --git a/src/coreclr/hosts/coreshim/CoreShim.cpp b/src/coreclr/hosts/coreshim/CoreShim.cpp
index 7a5c3a1d1c..238e40fb87 100644
--- a/src/coreclr/hosts/coreshim/CoreShim.cpp
+++ b/src/coreclr/hosts/coreshim/CoreShim.cpp
@@ -334,6 +334,7 @@ HRESULT coreclr::CreateTpaList(_Inout_ std::string &tpaList, _In_opt_z_ const WC
 
 coreclr::coreclr(_Inout_ AutoModule hmod)
     : _hmod{ std::move(hmod) }
+    , _attached{ false }
     , _clrInst{ nullptr }
     , _appDomainId{ std::numeric_limits<uint32_t>::max() }
 {
@@ -349,7 +350,7 @@ coreclr::coreclr(_Inout_ AutoModule hmod)
 
 coreclr::~coreclr()
 {
-    if (_clrInst != nullptr)
+    if (_clrInst != nullptr && !_attached)
     {
         HRESULT hr = _shutdown(_clrInst, _appDomainId);
         assert(SUCCEEDED(hr));
@@ -370,6 +371,21 @@ HRESULT coreclr::Initialize(
         appDomainName = "CoreShim";
 
     HRESULT hr;
+
+    // Check if this is hosted scenario - launched via CoreRun.exe
+    HMODULE mod = ::GetModuleHandleW(W("CoreRun.exe"));
+    if (mod != NULL)
+    {
+        using GetCurrentClrDetailsFunc = HRESULT(*)(void **clrInstance, unsigned int *appDomainId);
+        auto getCurrentClrDetails = (GetCurrentClrDetailsFunc)::GetProcAddress(mod, "GetCurrentClrDetails");
+        RETURN_IF_FAILED(getCurrentClrDetails(&_clrInst, &_appDomainId));
+        if (_clrInst != nullptr)
+        {
+            _attached = true;
+            return S_OK;
+        }
+    }
+
     try
     {
         const std::wstring exePathW = GetExePath();
diff --git a/src/coreclr/hosts/coreshim/CoreShim.h b/src/coreclr/hosts/coreshim/CoreShim.h
index d4c8b0aa6b..5875b457bc 100644
--- a/src/coreclr/hosts/coreshim/CoreShim.h
+++ b/src/coreclr/hosts/coreshim/CoreShim.h
@@ -174,6 +174,7 @@ public:
 private:
     AutoModule _hmod;
 
+    bool _attached;
     void *_clrInst;
     uint32_t _appDomainId;