Runtime changes for IJW Activation (#22636)

* Implement loading an assembly from an HMODULE on Windows.

* Use the native runtime to execute the main method so I don't have to replicate all of the startup behavior.

* If ijwhost is loaded, then call back into ijwhost to resolve tokens for vtable entries.

* Refactor our various component loaders (COM and IJW) and have IJW load components into separate ALCs when loaded from native.

* Move VTableFixups after DeliverSyncEvents in our incremental load. We need the module to be loaded to at least FILE_LOAD_DELIVER_EVENTS when resolving dependencies loaded via VTableFixups, otherwise they try to load into the default ALC.

* Only try to get ijwhost module handle on Windows.

* Use defined() instead of ifndef

* Fix off-Windows build break and fix unvalid comment.

* ComponentLoadContext->IsolatedComponentLoadContext

* Only build InMemoryAssemblyLoader when targeting windows.

* Add doc comments for IsolatedComponentLoadContext.

* Rename qcall.

* Add comment for boolean parameter.

* Add null check for managed ExecuteMainMethod entrypoint.

* Add comments in ceeload.cpp for the ijwhost method resolution.

* Add test verifying runtime callback to IJW host.

* Add test for InMemoryAssemblyLoader.LoadInMemoryAssembly.

* Fix x86 behavior rel. loading symbols by name and stdcall mangling.

* Remove exe entrypoints. The executable case for mixed-mode will go through the normal .NET Core app model (no special hosting support needed).

* Clean up whitespace

* Add test verifying M->N->M ALC switch behavior with IJW.

* Resolve the ijwhost module by probing the PE for the IJW assembly instead of hardcoding the name.

* Remove static caching in GetTokenGetterFromHostModule.

* Disable new IJW tests on Win7.

* PR Feedback.

* Cleanup extra copy of function.

* Use old-style environment checking in LoadIjwFromModuleHandle since we reference S.P.CL directly.

* Fix break in rebase

* Clean up fake mscoree code.

* Only validate that a CLR header exists. The OS verifies everything else.

* Make ijw host resolution code static to ceeload.cpp

* Use bracketed include for xplatform.h

* Update comment on _CorDllMain

* PR feedback.

* Remove .def file.

* PR feedback.

* Verify we export correctly on x86 and x64.

* Fix path to ijwhostmock for CopyConstructorMarshaler

* Disable IJW tests on arm32 nightly. Can't repro the dependency load failures. Fixes #23358

1 files changed, 66 insertions, 2 deletions

diff --git a/src/vm/ceeload.cpp b/src/vm/ceeload.cpp
index 1fec2c262d..b9cf4a7900 100644
--- a/src/vm/ceeload.cpp
+++ b/src/vm/ceeload.cpp
@@ -6482,6 +6482,59 @@ void Module::NotifyDebuggerUnload(AppDomain *pDomain)
 }
 
 #if !defined(CROSSGEN_COMPILE)
+using GetTokenForVTableEntry_t = mdToken(STDMETHODCALLTYPE*)(HMODULE module, BYTE**ppVTEntry);
+
+static HMODULE GetIJWHostForModule(Module* module)
+{
+#if !defined(FEATURE_PAL)
+    PEDecoder* pe = module->GetFile()->GetLoadedIL();
+
+    BYTE* baseAddress = (BYTE*)module->GetFile()->GetIJWBase();
+
+    IMAGE_IMPORT_DESCRIPTOR* importDescriptor = (IMAGE_IMPORT_DESCRIPTOR*)pe->GetDirectoryData(pe->GetDirectoryEntry(IMAGE_DIRECTORY_ENTRY_IMPORT));
+
+    for(; importDescriptor->Characteristics != 0; importDescriptor++)
+    {
+        IMAGE_THUNK_DATA* importNameTable = (IMAGE_THUNK_DATA*)pe->GetRvaData(importDescriptor->OriginalFirstThunk);
+
+        IMAGE_THUNK_DATA* importAddressTable = (IMAGE_THUNK_DATA*)pe->GetRvaData(importDescriptor->FirstThunk);
+
+        for (int thunkIndex = 0; importNameTable[thunkIndex].u1.AddressOfData != 0; thunkIndex++)
+        {
+            // The most significant bit will be set if the entry points to an ordinal.
+            if ((importNameTable[thunkIndex].u1.Ordinal & (1LL << (sizeof(importNameTable[thunkIndex].u1.Ordinal) * CHAR_BIT - 1))) == 0)
+            {
+                IMAGE_IMPORT_BY_NAME* nameImport = (IMAGE_IMPORT_BY_NAME*)(baseAddress + importNameTable[thunkIndex].u1.AddressOfData);
+                if (strcmp("_CorDllMain", nameImport->Name) == 0)
+                {
+                    HMODULE ijwHost;
+
+                    if (WszGetModuleHandleEx(
+                        GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT,
+                        (LPCWSTR)importAddressTable[thunkIndex].u1.Function,
+                        &ijwHost))
+                    {
+                        return ijwHost;
+                    }
+
+                }
+            }
+        }
+    }
+#endif
+    return nullptr;
+}
+
+static GetTokenForVTableEntry_t GetTokenGetterFromHostModule(HMODULE ijwHost)
+{
+    if (ijwHost != nullptr)
+    {
+        return (GetTokenForVTableEntry_t)GetProcAddress(ijwHost, "GetTokenForVTableEntry");
+    }
+
+    return nullptr;
+}
+
 //=================================================================================
 mdToken GetTokenForVTableEntry(HINSTANCE hInst, BYTE **ppVTEntry)
 {
@@ -6504,7 +6557,6 @@ void SetTargetForVTableEntry(HINSTANCE hInst, BYTE **ppVTEntry, BYTE *pTarget)
     DWORD oldProtect;
     if (!ClrVirtualProtect(ppVTEntry, sizeof(BYTE*), PAGE_READWRITE, &oldProtect))
     {
-        
         // This is very bad.  We are not going to be able to update header.
         _ASSERTE(!"SetTargetForVTableEntry(): VirtualProtect() changing IJW thunk vtable to R/W failed.\n");
         ThrowLastError();
@@ -6548,6 +6600,18 @@ void Module::FixupVTables()
         return;
     }
 
+    // Try getting a callback to the IJW host if it is loaded.
+    // The IJW host substitutes in special shims in the vtfixup table
+    // so if it is loaded, we need to query it for the tokens that were in the slots.
+    // If it is not loaded, then we know that the vtfixup table entries are tokens,
+    // so we can resolve them ourselves.
+    GetTokenForVTableEntry_t GetTokenForVTableEntryCallback = GetTokenGetterFromHostModule(GetIJWHostForModule(this));
+
+    if (GetTokenForVTableEntryCallback == nullptr)
+    {
+        GetTokenForVTableEntryCallback = GetTokenForVTableEntry;
+    }
+
     HINSTANCE hInstThis = GetFile()->GetIJWBase();
 
     // <REVISIT_TODO>@todo: workaround!</REVISIT_TODO>
@@ -6648,7 +6712,7 @@ void Module::FixupVTables()
                     {
                         if (pData->IsMethodFixedUp(iFixup, iMethod))
                             continue;
-                        mdToken mdTok = GetTokenForVTableEntry(hInstThis, (BYTE **)(pPointers + iMethod));
+                        mdToken mdTok = GetTokenForVTableEntryCallback(hInstThis, (BYTE**)(pPointers + iMethod));
                         CONSISTENCY_CHECK(mdTok != mdTokenNil);
                         rgMethodsToLoad[iCurMethod++].token = mdTok;
                     }