trying to hide JitHelper

src/coreclr/src/System.Private.CoreLib/src/System/Runtime/CompilerServices/CastHelpers.cs

@@ -177,6 +177,8 @@ private static CastResult ObjIsInstanceOfCached(object obj, void* toTypeHnd)
         // IsInstanceOf test used for unusual cases (naked type parameters, variant generic types)
         // Unlike the IsInstanceOfInterface, IsInstanceOfClass, and IsIsntanceofArray functions,
         // this test must deal with all kinds of type tests
+        [DebuggerStepThrough]
+        [DebuggerHidden]
         private static object? JIT_IsInstanceOfAny(void* toTypeHnd, object? obj)
         {
             CastResult result;
@@ -199,6 +201,8 @@ private static CastResult ObjIsInstanceOfCached(object obj, void* toTypeHnd)
         // ChkCast test used for unusual cases (naked type parameters, variant generic types)
         // Unlike the ChkCastInterface, ChkCastClass, and ChkCastArray functions,
         // this test must deal with all kinds of type tests
+        [DebuggerStepThrough]
+        [DebuggerHidden]
         private static object? JIT_ChkCastAny(void* toTypeHnd, object? obj)
         {
             CastResult result;

src/coreclr/src/debug/daccess/dacdbiimpl.cpp

@@ -5504,6 +5504,15 @@ IDacDbiInterface::DynamicMethodType DacDbiInterfaceImpl::IsILStubOrLCGMethod(VMP
     }
 }
 
+bool DacDbiInterfaceImpl::IsJitHelper(VMPTR_MethodDesc vmMethodDesc)
+{
+    DD_ENTER_MAY_THROW;
+
+    MethodDesc * pMD = vmMethodDesc.GetDacPtr();
+
+    return pMD->IsJitHelper();
+}
+
 //---------------------------------------------------------------------------------------
 //
 // Determine whether the specified thread is at a GC safe place.

src/coreclr/src/debug/daccess/dacdbiimpl.h

@@ -901,6 +901,8 @@ class DacDbiInterfaceImpl :
     // Check if the given method is an IL stub or an LCD method.
     DynamicMethodType IsILStubOrLCGMethod(VMPTR_MethodDesc vmMethodDesc);
 
+    bool IsJitHelper(VMPTR_MethodDesc vmMethodDesc);
+
     // Return a TargetBuffer for the raw vararg signature.
     TargetBuffer GetVarArgSig(CORDB_ADDRESS   VASigCookieAddr,
                               CORDB_ADDRESS * pArgBase);

src/coreclr/src/debug/di/rsstackwalk.cpp

@@ -707,7 +707,8 @@ HRESULT CordbStackWalk::GetFrameWorker(ICorDebugFrame ** ppFrame)
         // modified method, but at least the error won't leak out to interfere with inspection
         // of the callstack as a whole.
         if (!frameData.v.fNoMetadata &&
-            pNativeCode->GetFunction()->IsNativeImpl() != CordbFunction::kNativeOnly)
+            pNativeCode->GetFunction()->IsNativeImpl() != CordbFunction::kNativeOnly &&
+            !pDAC->IsJitHelper(pNativeCode->GetVMNativeCodeMethodDescToken()))
         {
             pNativeCode->LoadNativeInfo();
 

src/coreclr/src/debug/inc/dacdbiinterface.h

@@ -1630,6 +1630,9 @@ class IDacDbiInterface
     virtual
     DynamicMethodType IsILStubOrLCGMethod(VMPTR_MethodDesc vmMethodDesc) = 0;
 
+    virtual
+    bool IsJitHelper(VMPTR_MethodDesc vmMethodDesc) = 0;
+
     //
     // Return a TargetBuffer for the raw vararg signature.
     // Also return the address of the first argument in the vararg signature.

src/coreclr/src/vm/castcache.cpp

@@ -124,10 +124,12 @@ void CastCache::Initialize()
     CONTRACTL_END;
 
     MethodDesc* pMD = MscorlibBinder::GetMethod((BinderMethodID)(METHOD__CASTHELPERS__JIT_ISINSTANCEOFANY));
+    pMD->SetIsJitHelper();
     PCODE pDest = pMD->GetMultiCallableAddrOfCode();
     SetJitHelperFunction(CORINFO_HELP_ISINSTANCEOFANY, pDest);
 
     pMD = MscorlibBinder::GetMethod((BinderMethodID)(METHOD__CASTHELPERS__JIT_CHKCASTANY));
+    pMD->SetIsJitHelper();
     pDest = pMD->GetMultiCallableAddrOfCode();
     SetJitHelperFunction(CORINFO_HELP_CHKCASTANY, pDest);
 

src/coreclr/src/vm/excep.cpp

@@ -3518,7 +3518,9 @@ BOOL StackTraceInfo::AppendElement(BOOL bAllowAllocMem, UINT_PTR currentIP, UINT
     LOG((LF_EH, LL_INFO10000, "StackTraceInfo::AppendElement (%p), IP = %p, SP = %p, %s::%s\n", this, currentIP, currentSP, pFunc ? pFunc->m_pszDebugClassName : "", pFunc ? pFunc->m_pszDebugMethodName : "" ));
     BOOL bRetVal = FALSE;
 
-    if (pFunc != NULL && pFunc->IsILStub())
+    // TODO: WIP  is this actually the right place?
+    //       are there more places that should skip JIT helpers.
+    if (pFunc != NULL && (pFunc->IsILStub() || pFunc->IsJitHelper()))
         return FALSE;
 
     // Save this function in the stack trace array, which we only build on the first pass. We'll try to expand the

src/coreclr/src/vm/method.hpp

@@ -1845,7 +1845,9 @@ class MethodDesc
 
         enum_flag2_IsEligibleForTieredCompilation = 0x20,
 
-        // unused                           = 0x40,
+        //       for most purposes these are regular managed methods.
+        //       We do not want this to appear in stack traces though.
+        enum_flag2_IsJitHelper              = 0x40, 
         // unused                           = 0x80,
     };
     BYTE        m_bFlags2;
@@ -1908,6 +1910,18 @@ class MethodDesc
         m_bFlags2 |= enum_flag2_IsJitIntrinsic;
     }
 
+    inline BOOL IsJitHelper()
+    {
+        LIMITED_METHOD_DAC_CONTRACT;
+        return (m_bFlags2 & enum_flag2_IsJitHelper) != 0;
+    }
+
+    inline void SetIsJitHelper()
+    {
+        LIMITED_METHOD_CONTRACT;
+        m_bFlags2 |= enum_flag2_IsJitHelper;
+    }
+
     static const SIZE_T s_ClassificationSizeTable[];
 
     static SIZE_T GetBaseSize(DWORD classification)