Trim DBI frame data struct

src/coreclr/debug/daccess/dacdbiimplstackwalk.cpp

@@ -567,9 +567,6 @@ HRESULT STDMETHODCALLTYPE DacDbiInterfaceImpl::EnumerateInternalFrames(VMPTR_Thr
         Frame *     pFrame     = pThread->GetFrame();
         AppDomain * pAppDomain = AppDomain::GetCurrentDomain();
 
-        // This used to be only true for Enter-Managed chains.
-        // Since we don't have chains anymore, this can always be false.
-        frameData.quicklyUnwound = false;
         frameData.eType = DebuggerIPCE_STRData::cStubFrame;
 
         while (pFrame != FRAME_TOP)
@@ -791,10 +788,6 @@ void DacDbiInterfaceImpl::InitFrameData(StackFrameIterator *   pIter,
 
     pFrameData->fp = GetFramePointerWorker(pIter);
 
-    // This used to be only true for Enter-Managed chains.
-    // Since we don't have chains anymore, this can always be false.
-    pFrameData->quicklyUnwound = false;
-
     pFrameData->vmCurrentAppDomainToken.SetHostPtr(AppDomain::GetCurrentDomain());
 
     if (ft == kNativeRuntimeUnwindableStackFrame)

src/coreclr/debug/di/rspriv.h

@@ -6829,7 +6829,6 @@ class CordbNativeFrame : public CordbFrame, public ICorDebugNativeFrame, public
                      SIZE_T               ip,
                      DebuggerREGDISPLAY * pDRD,
                      TADDR                addrAmbientESP,
-                     bool                 fQuicklyUnwound,
                      CordbAppDomain *     pCurrentAppDomain,
                      CordbMiscFrame *     pMisc = NULL,
                      DT_CONTEXT *         pContext = NULL);
@@ -7009,9 +7008,6 @@ class CordbNativeFrame : public CordbFrame, public ICorDebugNativeFrame, public
     // the register set
     DebuggerREGDISPLAY m_rd;
 
-    // This field is only true for Enter-Managed chain.  It means that the register set is invalid.
-    bool               m_quicklyUnwound;
-
     // each CordbNativeFrame corresponds to exactly one CordbJITILFrame and one CordbNativeCode
     RSSmartPtr<CordbJITILFrame> m_JITILFrame;
     RSSmartPtr<CordbNativeCode> m_nativeCode;

src/coreclr/debug/di/rsstackwalk.cpp

@@ -683,7 +683,6 @@ HRESULT CordbStackWalk::GetFrameWorker(ICorDebugFrame ** ppFrame)
                                                               pJITFuncData->nativeOffset,
                                                               &(frameData.rd),
                                                               frameData.v.taAmbientESP,
-                                                              !!frameData.quicklyUnwound,
                                                               pCurrentAppDomain,
                                                               &miscFrame,
                                                               &(frameData.ctx));

src/coreclr/debug/di/rsthread.cpp

@@ -5483,13 +5483,11 @@ CordbNativeFrame::CordbNativeFrame(CordbThread *        pThread,
                                    SIZE_T               ip,
                                    DebuggerREGDISPLAY * pDRD,
                                    TADDR                taAmbientESP,
-                                   bool                 fQuicklyUnwound,
                                    CordbAppDomain *     pCurrentAppDomain,
                                    CordbMiscFrame *     pMisc /*= NULL*/,
                                    DT_CONTEXT *         pContext /*= NULL*/)
   : CordbFrame(pThread, fp, ip, pCurrentAppDomain),
     m_rd(*pDRD),
-    m_quicklyUnwound(fQuicklyUnwound),
     m_JITILFrame(NULL),
     m_nativeCode(pNativeCode), // implicit InternalAddRef
     m_taAmbientESP(taAmbientESP)
@@ -5854,7 +5852,7 @@ HRESULT CordbNativeFrame::GetRegisterSet(ICorDebugRegisterSet **ppRegisters)
         RSInitHolder<CordbRegisterSet> pRegisterSet(new CordbRegisterSet(&m_rd,
                                                                          m_pThread,
                                                                          IsLeafFrame(),
-                                                                         m_quicklyUnwound));
+                                                                         false));
 
         pRegisterSet.TransferOwnershipExternal(ppRegisters);
     }

src/coreclr/debug/ee/frameinfo.cpp

@@ -97,7 +97,6 @@ struct DebuggerFrameData
         this->fHitExitFrame = false;
 
         this->info.eStubFrameType = STUBFRAME_NONE;
-        this->info.quickUnwind = false;
 
         this->info.frame     = NULL;
         this->needParentInfo = false;
@@ -653,7 +652,6 @@ void FrameInfo::InitForUMChain(FramePointer fpRoot, REGDISPLAY * pRDSrc)
     CopyREGDISPLAY(&(this->registers), pRDSrc);
     this->fp = fpRoot;
 
-    this->quickUnwind = false;
     this->internal = false;
     this->managed = false;
 
@@ -750,7 +748,6 @@ void FrameInfo::InitFromStubHelper(
         this->fp = GetSP(pRDSrc);
     }
 
-    this->quickUnwind = false;
     this->internal    = false;
     this->managed     = true;
     this->relOffset   = 0;
@@ -846,7 +843,6 @@ void FrameInfo::InitForThreadStart(Thread * pThread, REGDISPLAY * pRDSrc)
     this->md = NULL;
     CopyREGDISPLAY(&(this->registers), pRDSrc);
     this->fp    = FramePointer::MakeFramePointer(pThread->GetCachedStackBase());
-    this->quickUnwind = false;
     this->internal = false;
     this->managed     = false;
     this->relOffset   = 0;
@@ -889,7 +885,6 @@ void FrameInfo::InitForEnterManagedChain(FramePointer fpRoot)
     memset((void *)&this->registers, 0, sizeof(this->registers));
     this->fp = fpRoot;
 
-    this->quickUnwind = true;
     this->internal    = false;
     this->managed     = true;
     this->relOffset   = 0;

src/coreclr/debug/ee/frameinfo.h

@@ -54,12 +54,6 @@ struct FrameInfo
     REGDISPLAY           registers;
     FramePointer         fp;
 
-    // This field is propagated to the right side to become CordbRegisterSet::m_quicklyUnwind.
-    // If it is true, then the registers reported in the REGDISPLAY are invalid.  It is only set to
-    // true in InitForEnterManagedChain().  In that case, we are passing a NULL REGDISPLAY anyway.
-    // This is such a misnomer.
-    bool                 quickUnwind;
-
     // Set to true if we are dealing with an internal explicit frame.  Currently this is only true
     // for prestub frames, security frames, funceval frames, and certain debugger-specific frames
     // (e.g. DebuggerClassInitMarkFrame).

src/coreclr/debug/inc/dbgipcevents.h

@@ -1365,28 +1365,18 @@ struct MSLAYOUT DebuggerIPCE_STRData
     // @dbgtodo  stackwalker/shim- Ideally we should be able to get rid of the DebuggerREGDISPLAY and just use the CONTEXT.
     DT_CONTEXT              ctx;
     DebuggerREGDISPLAY      rd;
-    bool                    quicklyUnwound;
-
     VMPTR_AppDomain         vmCurrentAppDomainToken;
 
 
     enum EType
     {
         cMethodFrame = 0,
-        cChain,
         cStubFrame,
         cRuntimeNativeFrame
     } eType;
 
     union MSLAYOUT
     {
-        // Data for a chain
-        struct MSLAYOUT
-        {
-            CorDebugChainReason chainReason;
-            bool                managed;
-        } u;
-
         // Data for a Method
         struct MSLAYOUT
         {