Delete DacDbi APIs AreGCStructuresValid and IsWinRTModule (#128014)

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Removes the DacDbi interface methods `AreGCStructuresValid` and
`IsWinRTModule` everywhere. Both native implementations were trivial
constants (`TRUE` and `FALSE` respectively), the managed cDAC mirrors
did the same, and only one in-tree caller existed.

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: rcj1 <77995559+rcj1@users.noreply.github.com>

Author: Copilot

src/coreclr/debug/daccess/dacdbiimpl.cpp

@@ -5948,20 +5948,6 @@ HRESULT STDMETHODCALLTYPE DacDbiInterfaceImpl::IsVmObjectHandleValid(VMPTR_OBJEC
     return hr;
 }
 
-// determines if the specified module is a WinRT module
-HRESULT STDMETHODCALLTYPE DacDbiInterfaceImpl::IsWinRTModule(VMPTR_Module vmModule, BOOL * pIsWinRT)
-{
-    if (pIsWinRT == NULL)
-        return E_POINTER;
-
-    DD_ENTER_MAY_THROW;
-
-    HRESULT hr = S_OK;
-    *pIsWinRT = FALSE;
-
-    return hr;
-}
-
 // Get the target address from a VMPTR_OBJECTHANDLE, i.e., the handle address
 HRESULT STDMETHODCALLTYPE DacDbiInterfaceImpl::GetHandleAddressFromVmHandle(VMPTR_OBJECTHANDLE vmHandle, OUT CORDB_ADDRESS * pRetVal)
 {
@@ -6420,17 +6406,6 @@ HRESULT STDMETHODCALLTYPE DacDbiInterfaceImpl::EnumerateMonitorEventWaitList(VMP
 }
 
 
-HRESULT STDMETHODCALLTYPE DacDbiInterfaceImpl::AreGCStructuresValid(OUT BOOL * pResult)
-{
-    HRESULT hr = S_OK;
-    EX_TRY
-    {
-        *pResult = TRUE;
-    }
-    EX_CATCH_HRESULT(hr);
-    return hr;
-}
-
 HeapData::HeapData()
     : YoungestGenPtr(0), YoungestGenLimit(0), Gen0Start(0), Gen0End(0), SegmentCount(0), Segments(0)
 {

src/coreclr/debug/daccess/dacdbiimpl.h

@@ -110,7 +110,6 @@ class DacDbiInterfaceImpl :
     HRESULT STDMETHODCALLTYPE IsThreadSuspendedOrHijacked(VMPTR_Thread vmThread, OUT BOOL * pResult);
 
 
-    HRESULT STDMETHODCALLTYPE AreGCStructuresValid(OUT BOOL * pResult);
     HRESULT STDMETHODCALLTYPE CreateHeapWalk(HeapWalkHandle *pHandle);
     HRESULT STDMETHODCALLTYPE DeleteHeapWalk(HeapWalkHandle handle);
 
@@ -847,9 +846,6 @@ class DacDbiInterfaceImpl :
     // Validate that the VMPTR_OBJECTHANDLE refers to a legitimate managed object
     HRESULT STDMETHODCALLTYPE IsVmObjectHandleValid(VMPTR_OBJECTHANDLE vmHandle, OUT BOOL * pResult);
 
-    // if the specified module is a WinRT module then isWinRT will equal TRUE
-    HRESULT STDMETHODCALLTYPE IsWinRTModule(VMPTR_Module vmModule, BOOL * pIsWinRT);
-
 private:
     // Check whether the specified thread is at a GC-safe place, i.e. in an interruptible region.
     BOOL IsThreadAtGCSafePlace(VMPTR_Thread vmThread);

src/coreclr/debug/daccess/dacimpl.h

@@ -1721,9 +1721,6 @@ DWORD DacGetNumHeaps();
  *   the event that we find heap corruption on a segment, or if the background
  *   GC is modifying a segment, the remainder of that segment will be skipped
  *   by design.
- * - The GC heap must be in a walkable state before you attempt to use this
- *   class on it.  The IDacDbiInterface::AreGCStructuresValid function will
- *   tell you whether it is safe to walk the heap or not.
  */
 class DacHeapWalker
 {

src/coreclr/debug/di/process.cpp

@@ -2165,18 +2165,9 @@ HRESULT CordbProcess::EnumerateHeap(ICorDebugHeapEnum **ppObjects)
 
     EX_TRY
     {
-        BOOL gcValid;
-        IfFailThrow(m_pDacPrimitives->AreGCStructuresValid(&gcValid));
-        if (gcValid)
-        {
-            CordbHeapEnum *pHeapEnum = new CordbHeapEnum(this);
-            GetContinueNeuterList()->Add(this, pHeapEnum);
-            hr = pHeapEnum->QueryInterface(__uuidof(ICorDebugHeapEnum), (void**)ppObjects);
-        }
-        else
-        {
-            hr = CORDBG_E_GC_STRUCTURES_INVALID;
-        }
+        CordbHeapEnum *pHeapEnum = new CordbHeapEnum(this);
+        GetContinueNeuterList()->Add(this, pHeapEnum);
+        hr = pHeapEnum->QueryInterface(__uuidof(ICorDebugHeapEnum), (void**)ppObjects);
     }
     EX_CATCH_HRESULT(hr);
 

src/coreclr/debug/inc/dacdbiinterface.h

@@ -1871,17 +1871,6 @@ IDacDbiInterface : public IUnknown
     //
     virtual HRESULT STDMETHODCALLTYPE IsVmObjectHandleValid(VMPTR_OBJECTHANDLE vmHandle, OUT BOOL * pResult) = 0;
 
-    // indicates if the specified module is a WinRT module
-    //
-    // Arguments:
-    //     vmModule: the module to check
-    //     pIsWinRT: [out] indicating state of module
-    //
-    // Return value:
-    //    S_OK on success; otherwise, an appropriate failure HRESULT.
-    //
-    virtual HRESULT STDMETHODCALLTYPE IsWinRTModule(VMPTR_Module vmModule, BOOL * pIsWinRT) = 0;
-
     // Determines the app domain id for the object referred to by a given VMPTR_OBJECTHANDLE
     //
     // Get the target address from a VMPTR_OBJECTHANDLE, i.e., the handle address
@@ -1954,11 +1943,6 @@ IDacDbiInterface : public IUnknown
 
     typedef void* * HeapWalkHandle;
 
-    // Returns true if it is safe to walk the heap.  If this function returns false,
-    // you could still create a heap walk and attempt to walk it, but there's no
-    // telling how much of the heap will be available.
-    virtual HRESULT STDMETHODCALLTYPE AreGCStructuresValid(OUT BOOL * pResult) = 0;
-
     // Creates a HeapWalkHandle which can be used to walk the managed heap with the
     // WalkHeap function.  Note if this function completes successfully you will need
     // to delete the handle by passing it into DeleteHeapWalk.
@@ -1976,9 +1960,7 @@ IDacDbiInterface : public IUnknown
     virtual HRESULT STDMETHODCALLTYPE DeleteHeapWalk(HeapWalkHandle handle) = 0;
 
     // Walks the heap using the given heap walk handle, enumerating objects
-    // on the managed heap.  Note that walking the heap requires that the GC
-    // data structures be in a valid state, which you can find by calling
-    // AreGCStructuresValid.
+    // on the managed heap.
     //
     // Arguments:
     //   handle   - a HeapWalkHandle obtained from CreateHeapWalk

src/coreclr/inc/dacdbi.idl

@@ -354,7 +354,6 @@ interface IDacDbiInterface : IUnknown
     // VM Object Handle
     HRESULT GetVmObjectHandle([in] CORDB_ADDRESS handleAddress, [out] VMPTR_OBJECTHANDLE * pRetVal);
     HRESULT IsVmObjectHandleValid([in] VMPTR_OBJECTHANDLE vmHandle, [out] BOOL * pResult);
-    HRESULT IsWinRTModule([in] VMPTR_Module vmModule, [out] BOOL * pIsWinRT);
     HRESULT GetHandleAddressFromVmHandle([in] VMPTR_OBJECTHANDLE vmHandle, [out] CORDB_ADDRESS * pRetVal);
 
     // Object Contents and Monitor
@@ -377,7 +376,6 @@ interface IDacDbiInterface : IUnknown
     HRESULT IsThreadSuspendedOrHijacked([in] VMPTR_Thread vmThread, [out] BOOL * pResult);
 
     // GC
-    HRESULT AreGCStructuresValid([out] BOOL * pResult);
     HRESULT CreateHeapWalk([out] HeapWalkHandle * pHandle);
     HRESULT DeleteHeapWalk([in] HeapWalkHandle handle);
     HRESULT WalkHeap([in] HeapWalkHandle handle, [in] ULONG count, [out] COR_HEAPOBJECT * objects, [out] ULONG * pFetched);

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/DacDbiImpl.cs

@@ -1540,23 +1540,6 @@ public int IsVmObjectHandleValid(ulong vmHandle, Interop.BOOL* pResult)
         return hr;
     }
 
-    public int IsWinRTModule(ulong vmModule, Interop.BOOL* isWinRT)
-    {
-        *isWinRT = Interop.BOOL.FALSE;
-        int hr = HResults.S_OK;
-#if DEBUG
-        if (_legacy is not null)
-        {
-            Interop.BOOL isWinRTLocal;
-            int hrLocal = _legacy.IsWinRTModule(vmModule, &isWinRTLocal);
-            Debug.ValidateHResult(hr, hrLocal);
-            if (hr == HResults.S_OK)
-                Debug.Assert(*isWinRT == isWinRTLocal, $"cDAC: {*isWinRT}, DAC: {isWinRTLocal}");
-        }
-#endif
-        return hr;
-    }
-
     public int GetHandleAddressFromVmHandle(ulong vmHandle, ulong* pRetVal)
     {
         *pRetVal = vmHandle;
@@ -1616,25 +1599,6 @@ public int GetMetaDataFileInfoFromPEFile(ulong vmPEAssembly, uint* dwTimeStamp,
     public int IsThreadSuspendedOrHijacked(ulong vmThread, Interop.BOOL* pResult)
         => LegacyFallbackHelper.CanFallback() && _legacy is not null ? _legacy.IsThreadSuspendedOrHijacked(vmThread, pResult) : HResults.E_NOTIMPL;
 
-    public int AreGCStructuresValid(Interop.BOOL* pResult)
-    {
-        // Native DacDbiInterfaceImpl::AreGCStructuresValid always returns TRUE.
-        // DacDbi callers assume the runtime is suspended, so GC structures are always valid.
-        *pResult = Interop.BOOL.TRUE;
-        int hr = HResults.S_OK;
-#if DEBUG
-        if (_legacy is not null)
-        {
-            Interop.BOOL resultLocal;
-            int hrLocal = _legacy.AreGCStructuresValid(&resultLocal);
-            Debug.ValidateHResult(hr, hrLocal);
-            if (hr == HResults.S_OK)
-                Debug.Assert(*pResult == resultLocal, $"cDAC: {*pResult}, DAC: {resultLocal}");
-        }
-#endif
-        return hr;
-    }
-
     public int CreateHeapWalk(nuint* pHandle)
         => LegacyFallbackHelper.CanFallback() && _legacy is not null ? _legacy.CreateHeapWalk(pHandle) : HResults.E_NOTIMPL;
 

src/native/managed/cdac/Microsoft.Diagnostics.DataContractReader.Legacy/Dbi/IDacDbiInterface.cs

@@ -458,9 +458,6 @@ public unsafe partial interface IDacDbiInterface
     [PreserveSig]
     int IsVmObjectHandleValid(ulong vmHandle, Interop.BOOL* pResult);
 
-    [PreserveSig]
-    int IsWinRTModule(ulong vmModule, Interop.BOOL* isWinRT);
-
     [PreserveSig]
     int GetHandleAddressFromVmHandle(ulong vmHandle, ulong* pRetVal);
 
@@ -482,9 +479,6 @@ public unsafe partial interface IDacDbiInterface
     [PreserveSig]
     int IsThreadSuspendedOrHijacked(ulong vmThread, Interop.BOOL* pResult);
 
-    [PreserveSig]
-    int AreGCStructuresValid(Interop.BOOL* pResult);
-
     [PreserveSig]
     int CreateHeapWalk(nuint* pHandle);
 

src/native/managed/cdac/tests/DumpTests/DacDbi/DacDbiAppDomainDumpTests.cs

@@ -1,7 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Collections.Generic;
 using Microsoft.Diagnostics.DataContractReader.Contracts;
 using Microsoft.Diagnostics.DataContractReader.Legacy;
 using Xunit;
@@ -92,28 +91,4 @@ public unsafe void GetTaskID_ReturnsZero(TestConfiguration config)
         Assert.Equal(System.HResults.S_OK, hr);
         Assert.Equal(0UL, taskId);
     }
-
-    [ConditionalTheory]
-    [MemberData(nameof(TestConfigurations))]
-    public unsafe void IsWinRTModule_ReturnsFalse(TestConfiguration config)
-    {
-        InitializeDumpTest(config);
-        DacDbiImpl dbi = CreateDacDbi();
-
-        ILoader loader = Target.Contracts.Loader;
-        TargetPointer appDomainPtr = Target.ReadGlobalPointer(Constants.Globals.AppDomain);
-        ulong appDomain = Target.ReadPointer(appDomainPtr);
-        IEnumerable<ModuleHandle> modules = loader.GetModuleHandles(new TargetPointer(appDomain),
-            AssemblyIterationFlags.IncludeLoaded | AssemblyIterationFlags.IncludeExecution);
-
-        foreach (ModuleHandle module in modules)
-        {
-            TargetPointer moduleAddr = loader.GetModule(module);
-            Interop.BOOL isWinRT;
-            int hr = dbi.IsWinRTModule(moduleAddr, &isWinRT);
-            Assert.Equal(System.HResults.S_OK, hr);
-            Assert.Equal(Interop.BOOL.FALSE, isWinRT);
-            break;
-        }
-    }
 }

src/native/managed/cdac/tests/DumpTests/DacDbi/DacDbiGCDumpTests.cs

@@ -18,21 +18,6 @@ public class DacDbiGCDumpTests : DumpTestBase
 
     private DacDbiImpl CreateDacDbi() => new DacDbiImpl(Target, legacyObj: null);
 
-    [ConditionalTheory]
-    [MemberData(nameof(TestConfigurations))]
-    public unsafe void AreGCStructuresValid_CrossValidateWithContract(TestConfiguration config)
-    {
-        InitializeDumpTest(config);
-        DacDbiImpl dbi = CreateDacDbi();
-
-        Interop.BOOL result;
-        int hr = dbi.AreGCStructuresValid(&result);
-        Assert.Equal(System.HResults.S_OK, hr);
-
-        bool contractResult = Target.Contracts.GC.GetGCStructuresValid();
-        Assert.Equal(contractResult, result == Interop.BOOL.TRUE);
-    }
-
     [ConditionalTheory]
     [MemberData(nameof(TestConfigurations))]
     public unsafe void GetGCHeapInformation_Succeeds(TestConfiguration config)