excep.cpp

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
//

//

/*  EXCEP.CPP:
 *
 */

#include "common.h"

#include "frames.h"
#include "threads.h"
#include "excep.h"
#include "object.h"
#include "field.h"
#include "dbginterface.h"
#include "cgensys.h"
#include "comutilnative.h"
#include "siginfo.hpp"
#include "gcheaputilities.h"
#include "eedbginterfaceimpl.h" //so we can clearexception in RealCOMPlusThrow
#include "dllimportcallback.h"
#include "stackwalk.h" //for CrawlFrame, in SetIPFromSrcToDst
#include "shimload.h"
#include "eeconfig.h"
#include "virtualcallstub.h"
#include "typestring.h"

#ifndef TARGET_UNIX
#include "dwreport.h"
#endif // !TARGET_UNIX

#include "eventreporter.h"

#ifdef FEATURE_COMINTEROP
#include<roerrorapi.h>
#endif
#ifdef FEATURE_EH_FUNCLETS
#include "exceptionhandling.h"
#endif

#include <errorrep.h>
#ifndef TARGET_UNIX
// Include definition of GenericModeBlock
#include <msodw.h>
#endif // TARGET_UNIX


// Support for extracting MethodDesc of a delegate.
#include "comdelegate.h"

#ifdef HAVE_GCCOVER
#include "gccover.h"
#endif // HAVE_GCCOVER

#ifndef TARGET_UNIX
// Windows uses 64kB as the null-reference area
#define NULL_AREA_SIZE   (64 * 1024)
#else // !TARGET_UNIX
#define NULL_AREA_SIZE   GetOsPageSize()
#endif // !TARGET_UNIX

#ifndef CROSSGEN_COMPILE

BOOL IsIPInEE(void *ip);

//----------------------------------------------------------------------------
//
// IsExceptionFromManagedCode - determine if pExceptionRecord points to a managed exception
//
// Arguments:
//    pExceptionRecord - pointer to exception record
//
// Return Value:
//    TRUE or FALSE
//
//----------------------------------------------------------------------------
BOOL IsExceptionFromManagedCode(const EXCEPTION_RECORD * pExceptionRecord)
{
    CONTRACTL {
        NOTHROW;
        GC_NOTRIGGER;
        SUPPORTS_DAC;
        PRECONDITION(CheckPointer(pExceptionRecord));
    } CONTRACTL_END;

    if (pExceptionRecord == NULL)
    {
        return FALSE;
    }

    DACCOP_IGNORE(FieldAccess, "EXCEPTION_RECORD is a OS structure, and ExceptionAddress is actually a target address here.");
    UINT_PTR address = reinterpret_cast<UINT_PTR>(pExceptionRecord->ExceptionAddress);

    // An exception code of EXCEPTION_COMPLUS indicates a managed exception
    // has occurred (most likely due to executing a "throw" instruction).
    //
    // Also, a hardware level exception may not have an exception code of
    // EXCEPTION_COMPLUS. In this case, an exception address that resides in
    // managed code indicates a managed exception has occurred.
    return (IsComPlusException(pExceptionRecord) ||
            (ExecutionManager::IsManagedCode((PCODE)address)));
}


#ifndef DACCESS_COMPILE

#define SZ_UNHANDLED_EXCEPTION W("Unhandled exception.")
#define SZ_UNHANDLED_EXCEPTION_CHARLEN ((sizeof(SZ_UNHANDLED_EXCEPTION) / sizeof(WCHAR)))


typedef struct {
    OBJECTREF pThrowable;
    STRINGREF s1;
    OBJECTREF pTmpThrowable;
} ProtectArgsStruct;

PEXCEPTION_REGISTRATION_RECORD GetCurrentSEHRecord();
BOOL IsUnmanagedToManagedSEHHandler(EXCEPTION_REGISTRATION_RECORD*);

VOID DECLSPEC_NORETURN RealCOMPlusThrow(OBJECTREF throwable, BOOL rethrow);

//-------------------------------------------------------------------------------
// Basically, this asks whether the exception is a managed exception thrown by
// this instance of the CLR.
//
// The way the result is used, however, is to decide whether this instance is the
// one to throw up the Watson box.
//-------------------------------------------------------------------------------
BOOL ShouldOurUEFDisplayUI(PEXCEPTION_POINTERS pExceptionInfo)
{
    STATIC_CONTRACT_NOTHROW;
    STATIC_CONTRACT_GC_NOTRIGGER;
    STATIC_CONTRACT_FORBID_FAULT;

    // Test first for the canned SO EXCEPTION_POINTERS structure as it has a NULL context record and will break the code below.
    extern EXCEPTION_POINTERS g_SOExceptionPointers;
    if (pExceptionInfo == &g_SOExceptionPointers)
    {
        return TRUE;
    }
    return IsComPlusException(pExceptionInfo->ExceptionRecord) || ExecutionManager::IsManagedCode(GetIP(pExceptionInfo->ContextRecord));
}

BOOL NotifyAppDomainsOfUnhandledException(
    PEXCEPTION_POINTERS pExceptionPointers,
    OBJECTREF   *pThrowableIn,
    BOOL        useLastThrownObject,
    BOOL        isTerminating);

VOID SetManagedUnhandledExceptionBit(
    BOOL        useLastThrownObject);

//-------------------------------------------------------------------------------
// This simply tests to see if the exception object is a subclass of
// the descriminating class specified in the exception clause.
//-------------------------------------------------------------------------------
BOOL ExceptionIsOfRightType(TypeHandle clauseType, TypeHandle thrownType)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_ANY;
        FORBID_FAULT;
    }
    CONTRACTL_END;

    // if not resolved to, then it wasn't loaded and couldn't have been thrown
    if (clauseType.IsNull())
        return FALSE;

    if (clauseType == thrownType)
        return TRUE;

    // now look for parent match
    TypeHandle superType = thrownType;
    while (!superType.IsNull()) {
        if (superType == clauseType) {
            break;
        }
        superType = superType.GetParent();
    }

    return !superType.IsNull();
}

//===========================================================================
// Gets the message text from an exception
//===========================================================================
ULONG GetExceptionMessage(OBJECTREF throwable,
                          __inout_ecount(bufferLength) LPWSTR buffer,
                          ULONG bufferLength)
{
    CONTRACTL
    {
        THROWS;
        GC_TRIGGERS;
        MODE_COOPERATIVE;
        INJECT_FAULT(ThrowOutOfMemory());
    }
    CONTRACTL_END;

    // Prefast buffer sanity check.  Don't call the API with a zero length buffer.
    if (bufferLength == 0)
    {
        _ASSERTE(bufferLength > 0);
        return 0;
    }

    StackSString result;
    GetExceptionMessage(throwable, result);

    ULONG length = result.GetCount();
    LPCWSTR chars = result.GetUnicode();

    if (length < bufferLength)
    {
        wcsncpy_s(buffer, bufferLength, chars, length);
    }
    else
    {
        wcsncpy_s(buffer, bufferLength, chars, bufferLength-1);
    }

    return length;
}

//-----------------------------------------------------------------------------
// Given an object, get the "message" from it.  If the object is an Exception
//  call Exception.ToString, otherwise, call Object.ToString
//-----------------------------------------------------------------------------
void GetExceptionMessage(OBJECTREF throwable, SString &result)
{
    CONTRACTL
    {
        THROWS;
        GC_TRIGGERS;
        MODE_COOPERATIVE;
        INJECT_FAULT(ThrowOutOfMemory());
    }
    CONTRACTL_END;

    STRINGREF pString = GetExceptionMessage(throwable);

    // If call returned NULL (not empty), oh well, no message.
    if (pString != NULL)
        pString->GetSString(result);
} // void GetExceptionMessage()

STRINGREF GetExceptionMessage(OBJECTREF throwable)
{
    CONTRACTL
    {
        THROWS;
        GC_TRIGGERS;
        MODE_COOPERATIVE;
        INJECT_FAULT(ThrowOutOfMemory());
    }
    CONTRACTL_END;

    // If there is no object, there is no message.
    if (throwable == NULL)
        return NULL;

    // Return value.
    STRINGREF pString = NULL;

    GCPROTECT_BEGIN(throwable);

    // Call Object.ToString(). Note that exceptions do not have to inherit from System.Exception
    MethodDescCallSite toString(METHOD__OBJECT__TO_STRING, &throwable);

    // Make the call.
    ARG_SLOT arg[1] = {ObjToArgSlot(throwable)};
    pString = toString.Call_RetSTRINGREF(arg);

    GCPROTECT_END();

    return pString;
}

HRESULT GetExceptionHResult(OBJECTREF throwable)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_COOPERATIVE;
    }
    CONTRACTL_END;

    HRESULT hr = E_FAIL;
    if (throwable == NULL)
        return hr;

    // Since any object can be thrown in managed code, not only instances of System.Exception subclasses
    // we need to check to see if we are dealing with an exception before attempting to retrieve
    // the HRESULT field. If we are not dealing with an exception, then we will simply return E_FAIL.
    _ASSERTE(IsException(throwable->GetMethodTable()));        // what is the pathway here?
    if (IsException(throwable->GetMethodTable()))
    {
        hr = ((EXCEPTIONREF)throwable)->GetHResult();
    }

    return hr;
} // HRESULT GetExceptionHResult()

DWORD GetExceptionXCode(OBJECTREF throwable)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_COOPERATIVE;
    }
    CONTRACTL_END;

    HRESULT hr = E_FAIL;
    if (throwable == NULL)
        return hr;

    // Since any object can be thrown in managed code, not only instances of System.Exception subclasses
    // we need to check to see if we are dealing with an exception before attempting to retrieve
    // the HRESULT field. If we are not dealing with an exception, then we will simply return E_FAIL.
    _ASSERTE(IsException(throwable->GetMethodTable()));        // what is the pathway here?
    if (IsException(throwable->GetMethodTable()))
    {
        hr = ((EXCEPTIONREF)throwable)->GetXCode();
    }

    return hr;
} // DWORD GetExceptionXCode()

//------------------------------------------------------------------------------
// This function will extract some information from an Access Violation SEH
//  exception, and store it in the System.AccessViolationException object.
// - the faulting instruction's IP.
// - the target address of the faulting instruction.
// - a code indicating attempted read vs write
//------------------------------------------------------------------------------
void SetExceptionAVParameters(              // No return.
    OBJECTREF throwable,                    // The object into which to set the values.
    EXCEPTION_RECORD *pExceptionRecord)     // The SEH exception information.
{
    CONTRACTL
    {
        THROWS;
        GC_TRIGGERS;
        MODE_COOPERATIVE;
        PRECONDITION(throwable != NULL);
    }
    CONTRACTL_END;

    GCPROTECT_BEGIN(throwable)
    {
        // This should only be called for AccessViolationException
        _ASSERTE(MscorlibBinder::GetException(kAccessViolationException) == throwable->GetMethodTable());

        FieldDesc *pFD_ip = MscorlibBinder::GetField(FIELD__ACCESS_VIOLATION_EXCEPTION__IP);
        FieldDesc *pFD_target = MscorlibBinder::GetField(FIELD__ACCESS_VIOLATION_EXCEPTION__TARGET);
        FieldDesc *pFD_access = MscorlibBinder::GetField(FIELD__ACCESS_VIOLATION_EXCEPTION__ACCESSTYPE);

        _ASSERTE(pFD_ip->GetFieldType() == ELEMENT_TYPE_I);
        _ASSERTE(pFD_target->GetFieldType() == ELEMENT_TYPE_I);
        _ASSERTE(pFD_access->GetFieldType() == ELEMENT_TYPE_I4);

        void *ip     = pExceptionRecord->ExceptionAddress;
        void *target = (void*)(pExceptionRecord->ExceptionInformation[1]);
        DWORD access = (DWORD)(pExceptionRecord->ExceptionInformation[0]);

        pFD_ip->SetValuePtr(throwable, ip);
        pFD_target->SetValuePtr(throwable, target);
        pFD_access->SetValue32(throwable, access);

    }
    GCPROTECT_END();

} // void SetExceptionAVParameters()

//------------------------------------------------------------------------------
// This will call InternalPreserveStackTrace (if the throwable derives from
//  System.Exception), to copy the stack trace to the _remoteStackTraceString.
// Doing so allows the stack trace of an exception caught by the runtime, and
//  rethrown with COMPlusThrow(OBJECTREF thowable), to be preserved.  Otherwise
//  the exception handling code may clear the stack trace.  (Generally, we see
//  the stack trace preserved on win32 and cleared on win64.)
//------------------------------------------------------------------------------
void ExceptionPreserveStackTrace(   // No return.
    OBJECTREF throwable)            // Object about to be thrown.
{
    CONTRACTL
    {
        THROWS;
        GC_TRIGGERS;
        MODE_COOPERATIVE;
        INJECT_FAULT(ThrowOutOfMemory());
    }
    CONTRACTL_END;

    // If there is no object, there is no stack trace to save.
    if (throwable == NULL)
        return;

    GCPROTECT_BEGIN(throwable);

    // Make sure it is derived from System.Exception, that it is not one of the
    //  preallocated exception objects, and that it has a stack trace to save.
    if (IsException(throwable->GetMethodTable()) &&
        !CLRException::IsPreallocatedExceptionObject(throwable))
    {
        LOG((LF_EH, LL_INFO1000, "ExceptionPreserveStackTrace called\n"));

        // Call Exception.InternalPreserveStackTrace() ...
        MethodDescCallSite preserveStackTrace(METHOD__EXCEPTION__INTERNAL_PRESERVE_STACK_TRACE, &throwable);

        // Make the call.
        ARG_SLOT arg[1] = {ObjToArgSlot(throwable)};
        preserveStackTrace.Call(arg);
    }

    GCPROTECT_END();

} // void ExceptionPreserveStackTrace()


// We have to cache the MethodTable and FieldDesc for wrapped non-compliant exceptions the first
// time we wrap, because we cannot tolerate a GC when it comes time to detect and unwrap one.

static MethodTable *pMT_RuntimeWrappedException;
static FieldDesc   *pFD_WrappedException;

// Non-compliant exceptions are immediately wrapped in a RuntimeWrappedException instance.  The entire
// exception system can now ignore the possibility of these cases except:
//
// 1) IL_Throw, which must wrap via this API
// 2) Calls to Filters & Catch handlers, which must unwrap based on whether the assembly is on the legacy
//    plan.
//
void WrapNonCompliantException(OBJECTREF *ppThrowable)
{
    CONTRACTL
    {
        THROWS;
        GC_TRIGGERS;
        MODE_COOPERATIVE;
        PRECONDITION(IsProtectedByGCFrame(ppThrowable));
    }
    CONTRACTL_END;

    _ASSERTE(!IsException((*ppThrowable)->GetMethodTable()));

    EX_TRY
    {
        // idempotent operations, so the race condition is okay.
        if (pMT_RuntimeWrappedException == NULL)
            pMT_RuntimeWrappedException = MscorlibBinder::GetException(kRuntimeWrappedException);

        if (pFD_WrappedException == NULL)
            pFD_WrappedException = MscorlibBinder::GetField(FIELD__RUNTIME_WRAPPED_EXCEPTION__WRAPPED_EXCEPTION);

        OBJECTREF orWrapper = AllocateObject(MscorlibBinder::GetException(kRuntimeWrappedException));

        GCPROTECT_BEGIN(orWrapper);

        MethodDescCallSite ctor(METHOD__RUNTIME_WRAPPED_EXCEPTION__OBJ_CTOR, &orWrapper);

        ARG_SLOT args[] =
        {
            ObjToArgSlot(orWrapper),
            ObjToArgSlot(*ppThrowable)
        };

        ctor.Call(args);

        *ppThrowable = orWrapper;

        GCPROTECT_END();
    }
    EX_CATCH
    {
        // If we took an exception while binding, or running the constructor of the RuntimeWrappedException
        // instance, we know that this new exception is CLS compliant.  In fact, it's likely to be
        // OutOfMemoryException, StackOverflowException or ThreadAbortException.
        OBJECTREF orReplacement = GET_THROWABLE();

        _ASSERTE(IsException(orReplacement->GetMethodTable()));

        *ppThrowable = orReplacement;

    } EX_END_CATCH(SwallowAllExceptions);
}

// Before presenting an exception object to a handler (filter or catch, not finally or fault), it
// may be necessary to turn it back into a non-compliant exception.  This is conditioned on an
// assembly level setting.
OBJECTREF PossiblyUnwrapThrowable(OBJECTREF throwable, Assembly *pAssembly)
{
    // Check if we are required to compute the RuntimeWrapExceptions status.
    BOOL fIsRuntimeWrappedException = ((throwable != NULL) && (throwable->GetMethodTable() == pMT_RuntimeWrappedException));
    BOOL fRequiresComputingRuntimeWrapExceptionsStatus = (fIsRuntimeWrappedException &&
                                                          (!(pAssembly->GetManifestModule()->IsRuntimeWrapExceptionsStatusComputed())));

    CONTRACTL
    {
        THROWS;
        // If we are required to compute the status of RuntimeWrapExceptions, then the operation could trigger a GC.
        // Thus, conditionally setup the contract.
        if (fRequiresComputingRuntimeWrapExceptionsStatus) GC_TRIGGERS; else GC_NOTRIGGER;
        MODE_COOPERATIVE;
        PRECONDITION(CheckPointer(pAssembly));
    }
    CONTRACTL_END;

    if (fIsRuntimeWrappedException && (!pAssembly->GetManifestModule()->IsRuntimeWrapExceptions()))
    {
        // We already created the instance, fetched the field.  We know it is
        // not marshal by ref, or any of the other cases that might trigger GC.
        ENABLE_FORBID_GC_LOADER_USE_IN_THIS_SCOPE();

        throwable = pFD_WrappedException->GetRefValue(throwable);
    }

    return throwable;
}


// This is used by a holder in CreateTypeInitializationExceptionObject to
// reset the state as appropriate.
void ResetTypeInitializationExceptionState(BOOL isAlreadyCreating)
{
    LIMITED_METHOD_CONTRACT;
    if (!isAlreadyCreating)
        GetThread()->ResetIsCreatingTypeInitException();
}

void CreateTypeInitializationExceptionObject(LPCWSTR pTypeThatFailed,
                                             OBJECTREF *pInnerException,
                                             OBJECTREF *pInitException,
                                             OBJECTREF *pThrowable)
{
    CONTRACTL {
        NOTHROW;
        GC_TRIGGERS;
        MODE_COOPERATIVE;
        PRECONDITION(CheckPointer(pInnerException, NULL_OK));
        PRECONDITION(CheckPointer(pInitException));
        PRECONDITION(CheckPointer(pThrowable));
        PRECONDITION(IsProtectedByGCFrame(pInnerException));
        PRECONDITION(IsProtectedByGCFrame(pInitException));
        PRECONDITION(IsProtectedByGCFrame(pThrowable));
        PRECONDITION(CheckPointer(GetThread()));
    } CONTRACTL_END;

    Thread *pThread  = GetThread();
    *pThrowable = NULL;

    // This will make sure to put the thread back to its original state if something
    // throws out of this function (like an OOM exception or something)
    Holder< BOOL, DoNothing< BOOL >, ResetTypeInitializationExceptionState, FALSE, NoNull< BOOL > >
        isAlreadyCreating(pThread->IsCreatingTypeInitException());

    EX_TRY {
        // This will contain the type of exception we want to create. Read comment below
        // on why we'd want to create an exception other than TypeInitException
        MethodTable *pMT;
        BinderMethodID methodID;

        // If we are already in the midst of creating a TypeInitializationException object,
        // and we get here, it means there was an exception thrown while initializing the
        // TypeInitializationException type itself, or one of the types used by its class
        // constructor. In this case, we're going to back down and use a SystemException
        // object in its place. It is *KNOWN* that both these exception types have identical
        // .ctor sigs "void instance (string, exception)" so both can be used interchangeably
        // in the code that follows.
        if (!isAlreadyCreating.GetValue()) {
            pThread->SetIsCreatingTypeInitException();
            pMT = MscorlibBinder::GetException(kTypeInitializationException);
            methodID = METHOD__TYPE_INIT_EXCEPTION__STR_EX_CTOR;
        }
        else {
            // If we ever hit one of these asserts, then it is bad
            // because we do not know what exception to return then.
            _ASSERTE(pInnerException != NULL);
            _ASSERTE(*pInnerException != NULL);
            *pThrowable = *pInnerException;
            *pInitException = *pInnerException;
            goto ErrExit;
        }

        // Allocate the exception object
        *pThrowable = AllocateObject(pMT);

        MethodDescCallSite ctor(methodID, pThrowable);

        // Since the inner exception object in the .ctor is of type Exception, make sure
        // that the object we're passed in derives from Exception. If not, pass NULL.
        BOOL isException = FALSE;
        if (pInnerException != NULL)
            isException = IsException((*pInnerException)->GetMethodTable());

        _ASSERTE(isException);      // What pathway can give us non-compliant exceptions?

        STRINGREF sType = StringObject::NewString(pTypeThatFailed);

        // If the inner object derives from exception, set it as the third argument.
        ARG_SLOT args[] = { ObjToArgSlot(*pThrowable),
                            ObjToArgSlot(sType),
                            ObjToArgSlot(isException ? *pInnerException : NULL) };

        // Call the .ctor
        ctor.Call(args);

        // On success, set the init exception.
        *pInitException = *pThrowable;
    }
    EX_CATCH {
        // If calling the constructor fails, then we'll call ourselves again, and this time
        // through we will try and create an EEException object. If that fails, then the
        // else block of this will be executed.
        if (!isAlreadyCreating.GetValue()) {
            CreateTypeInitializationExceptionObject(pTypeThatFailed, pInnerException, pInitException, pThrowable);
        }

        // If we were already in the middle of creating a type init
        // exception when we were called, we would have tried to create an EEException instead
        // of a TypeInitException.
        else {
            // If we're recursing, then we should be calling ourselves from DoRunClassInitThrowing,
            // in which case we're guaranteed that we're passing in all three arguments.
            *pInitException = pInnerException ? *pInnerException : NULL;
            *pThrowable = GET_THROWABLE();
        }
    } EX_END_CATCH(SwallowAllExceptions);

    CONSISTENCY_CHECK(*pInitException != NULL || !pInnerException);

 ErrExit:
    ;
}

// ==========================================================================
// ComputeEnclosingHandlerNestingLevel
//
//  This is code factored out of COMPlusThrowCallback to figure out
//  what the number of nested exception handlers is.
// ==========================================================================
DWORD ComputeEnclosingHandlerNestingLevel(IJitManager *pIJM,
                                          const METHODTOKEN& mdTok,
                                          SIZE_T offsNat)
{
    CONTRACTL
    {
        NOTHROW;
        GC_NOTRIGGER;
        MODE_ANY;
        FORBID_FAULT;
    }
    CONTRACTL_END;

    // Determine the nesting level of EHClause. Just walk the table
    // again, and find out how many handlers enclose it
    DWORD nestingLevel = 0;
    EH_CLAUSE_ENUMERATOR pEnumState;
    unsigned EHCount = pIJM->InitializeEHEnumeration(mdTok, &pEnumState);

    for (unsigned j=0; j<EHCount; j++)
    {
        EE_ILEXCEPTION_CLAUSE EHClause;

        pIJM->GetNextEHClause(&pEnumState,&EHClause);
        _ASSERTE(EHClause.HandlerEndPC != (DWORD) -1);  // <TODO> remove, only protects against a deprecated convention</TODO>

        if ((offsNat > EHClause.HandlerStartPC) &&
            (offsNat < EHClause.HandlerEndPC))
        {
            nestingLevel++;
        }
    }

    return nestingLevel;
}

// ******************************* EHRangeTreeNode ************************** //
EHRangeTreeNode::EHRangeTreeNode(void)
{
    WRAPPER_NO_CONTRACT;
    CommonCtor(0, false);
}

EHRangeTreeNode::EHRangeTreeNode(DWORD offset, bool fIsRange /* = false */)
{
    WRAPPER_NO_CONTRACT;
    CommonCtor(offset, fIsRange);
}

void EHRangeTreeNode::CommonCtor(DWORD offset, bool fIsRange)
{
    LIMITED_METHOD_CONTRACT;

    m_pTree = NULL;
    m_clause = NULL;

    m_pContainedBy = NULL;

    m_offset   = offset;
    m_fIsRange = fIsRange;
    m_fIsRoot  = false;      // must set this flag explicitly
}

inline bool EHRangeTreeNode::IsRange()
{
    // Please see the header file for an explanation of this assertion.
    _ASSERTE(m_fIsRoot || m_clause != NULL || !m_fIsRange);
    return m_fIsRange;
}

void EHRangeTreeNode::MarkAsRange()
{
    m_offset   = 0;
    m_fIsRange = true;
    m_fIsRoot  = false;
}

inline bool EHRangeTreeNode::IsRoot()
{
    // Please see the header file for an explanation of this assertion.
    _ASSERTE(m_fIsRoot || m_clause != NULL || !m_fIsRange);
    return m_fIsRoot;
}

void EHRangeTreeNode::MarkAsRoot(DWORD offset)
{
    m_offset   = offset;
    m_fIsRange = true;
    m_fIsRoot  = true;
}

inline DWORD EHRangeTreeNode::GetOffset()
{
    _ASSERTE(m_clause == NULL);
    _ASSERTE(IsRoot() || !IsRange());
    return m_offset;
}

inline DWORD EHRangeTreeNode::GetTryStart()
{
    _ASSERTE(IsRange());
    _ASSERTE(!IsRoot());
    if (IsRoot())
    {
        return 0;
    }
    else
    {
        return m_clause->TryStartPC;
    }
}

inline DWORD EHRangeTreeNode::GetTryEnd()
{
    _ASSERTE(IsRange());
    _ASSERTE(!IsRoot());
    if (IsRoot())
    {
        return GetOffset();
    }
    else
    {
        return m_clause->TryEndPC;
    }
}

inline DWORD EHRangeTreeNode::GetHandlerStart()
{
    _ASSERTE(IsRange());
    _ASSERTE(!IsRoot());
    if (IsRoot())
    {
        return 0;
    }
    else
    {
        return m_clause->HandlerStartPC;
    }
}

inline DWORD EHRangeTreeNode::GetHandlerEnd()
{
    _ASSERTE(IsRange());
    _ASSERTE(!IsRoot());
    if (IsRoot())
    {
        return GetOffset();
    }
    else
    {
        return m_clause->HandlerEndPC;
    }
}

inline DWORD EHRangeTreeNode::GetFilterStart()
{
    _ASSERTE(IsRange());
    _ASSERTE(!IsRoot());
    if (IsRoot())
    {
        return 0;
    }
    else
    {
        return m_clause->FilterOffset;
    }
}

// Get the end offset of the filter clause.  This offset is exclusive.
inline DWORD EHRangeTreeNode::GetFilterEnd()
{
    _ASSERTE(IsRange());
    _ASSERTE(!IsRoot());
    if (IsRoot())
    {
        // We should never get here if the "this" node is the root.
        // By definition, the root contains everything.  No checking is necessary.
        return 0;
    }
    else
    {
        return m_FilterEndPC;
    }
}

bool EHRangeTreeNode::Contains(DWORD offset)
{
    WRAPPER_NO_CONTRACT;

    EHRangeTreeNode node(offset);
    return Contains(&node);
}

bool EHRangeTreeNode::TryContains(DWORD offset)
{
    WRAPPER_NO_CONTRACT;

    EHRangeTreeNode node(offset);
    return TryContains(&node);
}

bool EHRangeTreeNode::HandlerContains(DWORD offset)
{
    WRAPPER_NO_CONTRACT;

    EHRangeTreeNode node(offset);
    return HandlerContains(&node);
}

bool EHRangeTreeNode::FilterContains(DWORD offset)
{
    WRAPPER_NO_CONTRACT;

    EHRangeTreeNode node(offset);
    return FilterContains(&node);
}

bool EHRangeTreeNode::Contains(EHRangeTreeNode* pNode)
{
    LIMITED_METHOD_CONTRACT;

    // If we are checking a range of address, then we should check the end address inclusively.
    if (pNode->IsRoot())
    {
        // No node contains the root node.
        return false;
    }
    else if (this->IsRoot())
    {
        return (pNode->IsRange() ?
                  (pNode->GetTryEnd() <= this->GetOffset()) && (pNode->GetHandlerEnd() <= this->GetOffset())
                : (pNode->GetOffset() < this->GetOffset()) );
    }
    else
    {
        return (this->TryContains(pNode) || this->HandlerContains(pNode) || this->FilterContains(pNode));
    }
}

bool EHRangeTreeNode::TryContains(EHRangeTreeNode* pNode)
{
    LIMITED_METHOD_CONTRACT;

    _ASSERTE(this->IsRange());

    if (pNode->IsRoot())
    {
        // No node contains the root node.
        return false;
    }
    else if (this->IsRoot())
    {
        // We will only get here from GetTcf() to determine if an address is in a try clause.
        // In this case we want to return false.
        return false;
    }
    else
    {
        DWORD tryStart = this->GetTryStart();
        DWORD tryEnd   = this->GetTryEnd();

        // If we are checking a range of address, then we should check the end address inclusively.
        if (pNode->IsRange())
        {
            DWORD start = pNode->GetTryStart();
            DWORD end   = pNode->GetTryEnd();

            if (start == tryStart && end == tryEnd)
            {
                return false;
            }
            else if (start == end)
            {
                // This is effectively a single offset.
                if ((tryStart <= start) && (end < tryEnd))
                {
                    return true;
                }
            }
            else if ((tryStart <= start) && (end <= tryEnd))
            {
                return true;
            }
        }
        else
        {
            DWORD offset = pNode->GetOffset();
            if ((tryStart <= offset) && (offset < tryEnd))
            {
                return true;
            }
        }
    }

#ifdef FEATURE_EH_FUNCLETS
    // If we are boot-strapping the tree, don't recurse down because the result could be unreliable.  Note that
    // even if we don't recurse, given a particular node, we can still always find its most specific container with
    // the logic above, i.e. it's always safe to do one depth level of checking.
    //
    // To build the tree, all we need to know is the most specific container of a particular node.  This can be
    // done by just comparing the offsets of the try regions.  However, funclets create a problem because even if
    // a funclet is conceptually contained in a try region, we cannot determine this fact just by comparing the offsets.
    // This is when we need to recurse the tree.  Here is a classic example:
    // try
    // {
    //     try
    //     {
    //     }
    //     catch
    //     {
    //         // If the offset is here, then we need to recurse.
    //     }
    // }
    // catch
    // {
    // }
    if (!m_pTree->m_fInitializing)
    {
        // Iterate all the contained clauses, and for the ones which are contained in the try region,
        // ask if the requested range is contained by it.
        USHORT i        = 0;
        USHORT numNodes = m_containees.Count();
        EHRangeTreeNode** ppNodes = NULL;
        for (i = 0, ppNodes = m_containees.Table(); i < numNodes; i++, ppNodes++)
        {
            // This variable is purely used for readability.
            EHRangeTreeNode* pNodeCur = *ppNodes;

            // it's possible for nested try blocks to have the same beginning and end offsets
            if ( ( this->GetTryStart()   <= pNodeCur->GetTryStart() ) &&
                 ( pNodeCur->GetTryEnd() <=  this->GetTryEnd()       ) )
            {
                if (pNodeCur->Contains(pNode))
                {
                    return true;
                }
            }
        }
    }
#endif // FEATURE_EH_FUNCLETS

    return false;
}

bool EHRangeTreeNode::HandlerContains(EHRangeTreeNode* pNode)
{
    LIMITED_METHOD_CONTRACT;

    _ASSERTE(this->IsRange());