private static void InvokeSecondPass(ref ExInfo exInfo, uint idxStart, uint idxLimit)
{
EHEnum ehEnum;
byte * pbMethodStartAddress;
if (!InternalCalls.RhpEHEnumInitFromStackFrameIterator(ref exInfo._frameIter, &pbMethodStartAddress, &ehEnum))
{
return;
}
byte *pbControlPC = exInfo._frameIter.ControlPC;
uint codeOffset = (uint)(pbControlPC - pbMethodStartAddress);
uint lastTryStart = 0, lastTryEnd = 0;
// Search the clauses for one that contains the current offset.
RhEHClause ehClause;
for (uint curIdx = 0; InternalCalls.RhpEHEnumNext(&ehEnum, &ehClause) && curIdx < idxLimit; curIdx++)
{
//
// Skip to the starting try region. This is used by collided unwinds and rethrows to pickup where
// the previous dispatch left off.
//
if (idxStart != MaxTryRegionIdx)
{
if (curIdx <= idxStart)
{
lastTryStart = ehClause._tryStartOffset; lastTryEnd = ehClause._tryEndOffset;
continue;
}
// Now, we continue skipping while the try region is identical to the one that invoked the
// previous dispatch.
if ((ehClause._tryStartOffset == lastTryStart) && (ehClause._tryEndOffset == lastTryEnd))
{
continue;
}
// We are done skipping. This is required to handle empty finally block markers that are used
// to separate runs of different try blocks with same native code offsets.
idxStart = MaxTryRegionIdx;
}
RhEHClauseKind clauseKind = ehClause._clauseKind;
if ((clauseKind != RhEHClauseKind.RH_EH_CLAUSE_FAULT) ||
!ehClause.ContainsCodeOffset(codeOffset))
{
continue;
}
// Found a containing clause. Because of the order of the clauses, we know this is the
// most containing.
// N.B. -- We need to suppress GC "in-between" calls to finallys in this loop because we do
// not have the correct next-execution point live on the stack and, therefore, may cause a GC
// hole if we allow a GC between invocation of finally funclets (i.e. after one has returned
// here to the dispatcher, but before the next one is invoked). Once they are running, it's
// fine for them to trigger a GC, obviously.
//
// As a result, RhpCallFinallyFunclet will set this state in the runtime upon return from the
// funclet, and we need to reset it if/when we fall out of the loop and we know that the
// method will no longer get any more GC callbacks.
byte *pFinallyHandler = ehClause._handlerAddress;
exInfo._idxCurClause = curIdx;
InternalCalls.RhpCallFinallyFunclet(pFinallyHandler, exInfo._frameIter.RegisterSet);
exInfo._idxCurClause = MaxTryRegionIdx;
}
}
// Retrieve the offset of the value embedded in a Nullable<T>.
internal unsafe byte GetNullableValueOffset()
{
fixed(EEType *pThis = &this)
return(InternalCalls.RhpGetNullableEETypeValueOffset(pThis));
}
internal IntPtr GetSealedVirtualSlot(ushort index)
{
fixed(EEType *pThis = &this)
return(InternalCalls.RhpGetSealedVirtualSlot(pThis, index));
}
private static bool FindImplSlotInSimpleMap(EEType *pTgtType,
EEType *pItfType,
UInt32 itfSlotNumber,
UInt16 *pImplSlotNumber,
bool actuallyCheckVariance)
{
Debug.Assert(pTgtType->HasDispatchMap, "Missing dispatch map");
EEType * pItfOpenGenericType = null;
EETypeRef * pItfInstantiation = null;
int itfArity = 0;
GenericVariance *pItfVarianceInfo = null;
bool fCheckVariance = false;
bool fArrayCovariance = false;
if (actuallyCheckVariance)
{
fCheckVariance = pItfType->HasGenericVariance;
fArrayCovariance = pTgtType->IsArray;
// Non-arrays can follow array variance rules iff
// 1. They have one generic parameter
// 2. That generic parameter is array covariant.
//
// This special case is to allow array enumerators to work
if (!fArrayCovariance && pTgtType->HasGenericVariance)
{
EETypeRef * pTgtInstantiation;
int tgtEntryArity;
GenericVariance *pTgtVarianceInfo;
EEType * pTgtEntryGenericType = InternalCalls.RhGetGenericInstantiation(pTgtType,
&tgtEntryArity,
&pTgtInstantiation,
&pTgtVarianceInfo);
if ((tgtEntryArity == 1) && pTgtVarianceInfo[0] == GenericVariance.ArrayCovariant)
{
fArrayCovariance = true;
}
}
// Arrays are covariant even though you can both get and set elements (type safety is maintained by
// runtime type checks during set operations). This extends to generic interfaces implemented on those
// arrays. We handle this by forcing all generic interfaces on arrays to behave as though they were
// covariant (over their one type parameter corresponding to the array element type).
if (fArrayCovariance && pItfType->IsGeneric)
{
fCheckVariance = true;
}
// If there is no variance checking, there is no operation to perform. (The non-variance check loop
// has already completed)
if (!fCheckVariance)
{
return(false);
}
}
DispatchMap * pMap = pTgtType->DispatchMap;
DispatchMapEntry *i = &pMap->_dispatchMap;
DispatchMapEntry *iEnd = (&pMap->_dispatchMap) + pMap->_entryCount;
for (; i != iEnd; ++i)
{
if (i->_usInterfaceMethodSlot == itfSlotNumber)
{
EEType *pCurEntryType =
pTgtType->InterfaceMap[i->_usInterfaceIndex].InterfaceType;
if (pCurEntryType->IsCloned)
{
pCurEntryType = pCurEntryType->CanonicalEEType;
}
if (pCurEntryType == pItfType)
{
*pImplSlotNumber = i->_usImplMethodSlot;
return(true);
}
else if (fCheckVariance && ((fArrayCovariance && pCurEntryType->IsGeneric) || pCurEntryType->HasGenericVariance))
{
// Interface types don't match exactly but both the target interface and the current interface
// in the map are marked as being generic with at least one co- or contra- variant type
// parameter. So we might still have a compatible match.
// Retrieve the unified generic instance for the callsite interface if we haven't already (we
// lazily get this then cache the result since the lookup isn't necessarily cheap).
if (pItfOpenGenericType == null)
{
pItfOpenGenericType = InternalCalls.RhGetGenericInstantiation(pItfType,
&itfArity,
&pItfInstantiation,
&pItfVarianceInfo);
}
// Retrieve the unified generic instance for the interface we're looking at in the map.
// Grab instantiation details for the candidate interface.
EETypeRef * pCurEntryInstantiation;
int curEntryArity;
GenericVariance *pCurEntryVarianceInfo;
EEType * pCurEntryGenericType = InternalCalls.RhGetGenericInstantiation(pCurEntryType,
&curEntryArity,
&pCurEntryInstantiation,
&pCurEntryVarianceInfo);
// If the generic types aren't the same then the types aren't compatible.
if (pItfOpenGenericType != pCurEntryGenericType)
{
continue;
}
// The types represent different instantiations of the same generic type. The
// arity of both had better be the same.
Debug.Assert(itfArity == curEntryArity, "arity mismatch betweeen generic instantiations");
if (TypeCast.TypeParametersAreCompatible(itfArity, pCurEntryInstantiation, pItfInstantiation, pItfVarianceInfo, fArrayCovariance))
{
*pImplSlotNumber = i->_usImplMethodSlot;
return(true);
}
}
}
}
return(false);
}
// Retrieve the value type T from a Nullable<T>.
internal unsafe EEType *GetNullableType()
{
fixed(EEType *pThis = &this)
return(InternalCalls.RhpGetNullableEEType(pThis));
}
private static void DispatchEx(ref StackFrameIterator frameIter, ref ExInfo exInfo, uint startIdx)
{
Debug.Assert(exInfo._passNumber == 1, "expected asm throw routine to set the pass");
object exceptionObj = exInfo.ThrownException;
// ------------------------------------------------
//
// First pass
//
// ------------------------------------------------
UIntPtr handlingFrameSP = MaxSP;
byte * pCatchHandler = null;
uint catchingTryRegionIdx = MaxTryRegionIdx;
bool isFirstRethrowFrame = (startIdx != MaxTryRegionIdx);
bool isFirstFrame = true;
byte * prevControlPC = null;
UIntPtr prevFramePtr = UIntPtr.Zero;
bool unwoundReversePInvoke = false;
bool isValid = frameIter.Init(exInfo._pExContext);
Debug.Assert(isValid, "RhThrowEx called with an unexpected context");
DebuggerNotify.BeginFirstPass(exceptionObj, frameIter.ControlPC, frameIter.SP);
for (; isValid; isValid = frameIter.Next(out startIdx, out unwoundReversePInvoke))
{
// For GC stackwalking, we'll happily walk across native code blocks, but for EH dispatch, we
// disallow dispatching exceptions across native code.
if (unwoundReversePInvoke)
{
break;
}
prevControlPC = frameIter.ControlPC;
DebugScanCallFrame(exInfo._passNumber, frameIter.ControlPC, frameIter.SP);
// A debugger can subscribe to get callbacks at a specific frame of exception dispatch
// exInfo._notifyDebuggerSP can be populated by the debugger from out of process
// at any time.
if (exInfo._notifyDebuggerSP == frameIter.SP)
{
DebuggerNotify.FirstPassFrameEntered(exceptionObj, frameIter.ControlPC, frameIter.SP);
}
UpdateStackTrace(exceptionObj, ref exInfo, ref isFirstRethrowFrame, ref prevFramePtr, ref isFirstFrame);
byte *pHandler;
if (FindFirstPassHandler(exceptionObj, startIdx, ref frameIter,
out catchingTryRegionIdx, out pHandler))
{
handlingFrameSP = frameIter.SP;
pCatchHandler = pHandler;
DebugVerifyHandlingFrame(handlingFrameSP);
break;
}
}
DebuggerNotify.EndFirstPass(exceptionObj, pCatchHandler, handlingFrameSP);
if (pCatchHandler == null)
{
UnhandledExceptionFailFastViaClasslib(
RhFailFastReason.PN_UnhandledException,
exceptionObj,
(IntPtr)prevControlPC, // IP of the last frame that did not handle the exception
ref exInfo);
}
// We FailFast above if the exception goes unhandled. Therefore, we cannot run the second pass
// without a catch handler.
Debug.Assert(pCatchHandler != null, "We should have a handler if we're starting the second pass");
DebuggerNotify.BeginSecondPass();
// ------------------------------------------------
//
// Second pass
//
// ------------------------------------------------
// Due to the stackwalker logic, we cannot tolerate triggering a GC from the dispatch code once we
// are in the 2nd pass. This is because the stackwalker applies a particular unwind semantic to
// 'collapse' funclets which gets confused when we walk out of the dispatch code and encounter the
// 'main body' without first encountering the funclet. The thunks used to invoke 2nd-pass
// funclets will always toggle this mode off before invoking them.
InternalCalls.RhpSetThreadDoNotTriggerGC();
exInfo._passNumber = 2;
startIdx = MaxTryRegionIdx;
isValid = frameIter.Init(exInfo._pExContext);
for (; isValid && ((byte *)frameIter.SP <= (byte *)handlingFrameSP); isValid = frameIter.Next(out startIdx))
{
Debug.Assert(isValid, "second-pass EH unwind failed unexpectedly");
DebugScanCallFrame(exInfo._passNumber, frameIter.ControlPC, frameIter.SP);
if (frameIter.SP == handlingFrameSP)
{
// invoke only a partial second-pass here...
InvokeSecondPass(ref exInfo, startIdx, catchingTryRegionIdx);
break;
}
InvokeSecondPass(ref exInfo, startIdx);
}
// ------------------------------------------------
//
// Call the handler and resume execution
//
// ------------------------------------------------
exInfo._idxCurClause = catchingTryRegionIdx;
InternalCalls.RhpCallCatchFunclet(
exceptionObj, pCatchHandler, frameIter.RegisterSet, ref exInfo);
// currently, RhpCallCatchFunclet will resume after the catch
Debug.Assert(false, "unreachable");
FallbackFailFast(RhFailFastReason.InternalError, null);
}
public unsafe static IntPtr GetNewThunksBlock()
{
IntPtr nextThunkMapBlock;
// Check the most recently mapped thunks block. Each mapping consists of multiple
// thunk stubs pages, and multiple thunk data pages (typically 8 pages of each in a single mapping)
if (s_currentlyMappedThunkBlocksIndex < Constants.NumThunkBlocksPerMapping)
{
nextThunkMapBlock = s_currentlyMappedThunkBlocks[s_currentlyMappedThunkBlocksIndex++];
#if DEBUG
s_currentlyMappedThunkBlocks[s_currentlyMappedThunkBlocksIndex - 1] = IntPtr.Zero;
Debug.Assert(nextThunkMapBlock != IntPtr.Zero);
#endif
}
else
{
if (s_thunksTemplate == IntPtr.Zero)
{
// First, we use the thunks directly from the thunks template sections in the module until all
// thunks in that template are used up.
s_thunksTemplate = nextThunkMapBlock = InternalCalls.RhpGetThunksBase();
}
else
{
// Compute and cache the current module's base address and the RVA of the thunks template
if (s_thunksModuleBaseAddress == IntPtr.Zero)
{
EEType *pInstanceType = (new ThunkBlocks()).EEType;
s_thunksModuleBaseAddress = InternalCalls.RhGetModuleFromPointer(pInstanceType);
IntPtr thunkBase = InternalCalls.RhpGetThunksBase();
Debug.Assert(thunkBase != IntPtr.Zero);
s_thunksTemplateRva = (int)(((nuint)thunkBase) - ((nuint)s_thunksModuleBaseAddress));
Debug.Assert(s_thunksTemplateRva % (int)Constants.AllocationGranularity == 0);
}
// We've already used the thunks tempate in the module for some previous thunks, and we
// cannot reuse it here. Now we need to create a new mapping of the thunks section in order to have
// more thunks
nextThunkMapBlock = InternalCalls.RhAllocateThunksFromTemplate(
s_thunksModuleBaseAddress,
s_thunksTemplateRva,
(int)(Constants.NumThunkBlocksPerMapping * Constants.PageSize * 2));
if (nextThunkMapBlock == IntPtr.Zero)
{
// We either ran out of memory and can't do anymore mappings of the thunks templates sections,
// or we are using the managed runtime services fallback, which doesn't provide the
// file mapping feature (ex: older version of mrt100.dll, or no mrt100.dll at all).
// The only option is for the caller to attempt and recycle unused thunks to be able to
// find some free entries.
InternalCalls.RhpReleaseThunkPoolLock();
return(IntPtr.Zero);
}
}
// Each mapping consists of multiple blocks of thunk stubs/data pairs. Keep track of those
// so that we do not create a new mapping until all blocks in the sections we just mapped are consumed
for (int i = 0; i < Constants.NumThunkBlocksPerMapping; i++)
{
s_currentlyMappedThunkBlocks[i] = nextThunkMapBlock + (int)(Constants.PageSize * i * 2);
}
s_currentlyMappedThunkBlocksIndex = 1;
}
Debug.Assert(nextThunkMapBlock != IntPtr.Zero);
// Setup the thunks in the new block as a linked list of thunks.
// Use the first data field of the thunk to build the linked list.
int numThunksPerBlock = Constants.NumThunksPerBlock;
IntPtr dataAddress = nextThunkMapBlock + (int)Constants.PageSize;
for (int i = 0; i < numThunksPerBlock; i++)
{
Debug.Assert(dataAddress == nextThunkMapBlock + (int)(Constants.PageSize + i * 2 * IntPtr.Size));
if (i == (numThunksPerBlock - 1))
{
*((IntPtr *)(dataAddress)) = IntPtr.Zero;
}
else
{
*((IntPtr *)(dataAddress)) = dataAddress + 2 * IntPtr.Size;
}
#if DEBUG
// Debug flag in the second data cell indicating the thunk is not used
*((IntPtr *)(dataAddress + IntPtr.Size)) = new IntPtr(-1);
#endif
dataAddress += 2 * IntPtr.Size;
}
return(nextThunkMapBlock);
}
public static void RhThrowHwEx(uint exceptionCode, ref ExInfo exInfo)
{
// trigger a GC (only if gcstress) to ensure we can stackwalk at this point
GCStress.TriggerGC();
InternalCalls.RhpValidateExInfoStack();
IntPtr faultingCodeAddress = exInfo._pExContext->IP;
bool instructionFault = true;
ExceptionIDs exceptionId = default(ExceptionIDs);
Exception? exceptionToThrow = null;
switch (exceptionCode)
{
case (uint)HwExceptionCode.STATUS_REDHAWK_NULL_REFERENCE:
exceptionId = ExceptionIDs.NullReference;
break;
case (uint)HwExceptionCode.STATUS_REDHAWK_UNMANAGED_HELPER_NULL_REFERENCE:
// The write barrier where the actual fault happened has been unwound already.
// The IP of this fault needs to be treated as return address, not as IP of
// faulting instruction.
instructionFault = false;
exceptionId = ExceptionIDs.NullReference;
break;
case (uint)HwExceptionCode.STATUS_REDHAWK_THREAD_ABORT:
exceptionToThrow = InternalCalls.RhpGetThreadAbortException();
break;
case (uint)HwExceptionCode.STATUS_DATATYPE_MISALIGNMENT:
exceptionId = ExceptionIDs.DataMisaligned;
break;
// N.B. -- AVs that have a read/write address lower than 64k are already transformed to
// HwExceptionCode.REDHAWK_NULL_REFERENCE prior to calling this routine.
case (uint)HwExceptionCode.STATUS_ACCESS_VIOLATION:
exceptionId = ExceptionIDs.AccessViolation;
break;
case (uint)HwExceptionCode.STATUS_INTEGER_DIVIDE_BY_ZERO:
exceptionId = ExceptionIDs.DivideByZero;
break;
case (uint)HwExceptionCode.STATUS_INTEGER_OVERFLOW:
exceptionId = ExceptionIDs.Overflow;
break;
default:
// We don't wrap SEH exceptions from foreign code like CLR does, so we believe that we
// know the complete set of HW faults generated by managed code and do not need to handle
// this case.
FailFastViaClasslib(RhFailFastReason.InternalError, null, faultingCodeAddress);
break;
}
if (exceptionId != default(ExceptionIDs))
{
exceptionToThrow = GetClasslibException(exceptionId, faultingCodeAddress);
}
exInfo.Init(exceptionToThrow !, instructionFault);
DispatchEx(ref exInfo._frameIter, ref exInfo, MaxTryRegionIdx);
FallbackFailFast(RhFailFastReason.InternalError, null);
}
public static int RhGetThunkSize()
{
return(InternalCalls.RhpGetThunkSize());
}
static internal unsafe bool ImplementsInterface(EEType *pObjType, EEType *pTargetType)
{
Debug.Assert(!pTargetType->IsParameterizedType, "did not expect paramterized type");
Debug.Assert(pTargetType->IsInterface, "IsInstanceOfInterface called with non-interface EEType");
// This can happen with generic interface types
// Debug.Assert(!pTargetType->IsCloned, "cloned interface types are disallowed");
// canonicalize target type
if (pTargetType->IsCloned)
{
pTargetType = pTargetType->CanonicalEEType;
}
int numInterfaces = pObjType->NumInterfaces;
EEInterfaceInfo *interfaceMap = pObjType->InterfaceMap;
for (int i = 0; i < numInterfaces; i++)
{
EEType *pInterfaceType = interfaceMap[i].InterfaceType;
// canonicalize the interface type
if (pInterfaceType->IsCloned)
{
pInterfaceType = pInterfaceType->CanonicalEEType;
}
if (pInterfaceType == pTargetType)
{
return(true);
}
}
// We did not find the interface type in the list of supported interfaces. There's still one
// chance left: if the target interface is generic and one or more of its type parameters is co or
// contra variant then the object can still match if it implements a different instantiation of
// the interface with type compatible generic arguments.
//
// Interfaces which are only variant for arrays have the HasGenericVariance flag set even if they
// are not variant.
bool fArrayCovariance = pObjType->IsArray;
if (pTargetType->HasGenericVariance)
{
// Grab details about the instantiation of the target generic interface.
EETypeRef * pTargetInstantiation;
int targetArity;
GenericVariance *pTargetVarianceInfo;
EEType * pTargetGenericType = InternalCalls.RhGetGenericInstantiation(pTargetType,
&targetArity,
&pTargetInstantiation,
&pTargetVarianceInfo);
Debug.Assert(pTargetVarianceInfo != null, "did not expect empty variance info");
for (int i = 0; i < numInterfaces; i++)
{
EEType *pInterfaceType = interfaceMap[i].InterfaceType;
// We can ignore interfaces which are not also marked as having generic variance
// unless we're dealing with array covariance.
//
// Interfaces which are only variant for arrays have the HasGenericVariance flag set even if they
// are not variant.
if (pInterfaceType->HasGenericVariance)
{
// Grab instantiation details for the candidate interface.
EETypeRef * pInterfaceInstantiation;
int interfaceArity;
GenericVariance *pInterfaceVarianceInfo;
EEType * pInterfaceGenericType = InternalCalls.RhGetGenericInstantiation(pInterfaceType,
&interfaceArity,
&pInterfaceInstantiation,
&pInterfaceVarianceInfo);
Debug.Assert(pInterfaceVarianceInfo != null, "did not expect empty variance info");
// If the generic types aren't the same then the types aren't compatible.
if (pInterfaceGenericType != pTargetGenericType)
{
continue;
}
// The types represent different instantiations of the same generic type. The
// arity of both had better be the same.
Debug.Assert(targetArity == interfaceArity, "arity mismatch betweeen generic instantiations");
// Compare the instantiations to see if they're compatible taking variance into account.
if (TypeParametersAreCompatible(targetArity,
pInterfaceInstantiation,
pTargetInstantiation,
pTargetVarianceInfo,
fArrayCovariance))
{
return(true);
}
}
}
}
return(false);
}
public static unsafe IntPtr GetNewThunksBlock()
{
IntPtr nextThunksBlock;
// Check the most recently mapped thunks block. Each mapping consists of multiple
// thunk stubs pages, and multiple thunk data pages (typically 8 pages of each in a single mapping)
if (s_currentlyMappedThunkBlocksIndex < Constants.NumThunkBlocksPerMapping)
{
nextThunksBlock = s_currentlyMappedThunkBlocks[s_currentlyMappedThunkBlocksIndex++];
#if DEBUG
s_currentlyMappedThunkBlocks[s_currentlyMappedThunkBlocksIndex - 1] = IntPtr.Zero;
Debug.Assert(nextThunksBlock != IntPtr.Zero);
#endif
}
else
{
nextThunksBlock = InternalCalls.RhAllocateThunksMapping();
if (nextThunksBlock == IntPtr.Zero)
{
// We either ran out of memory and can't do anymore mappings of the thunks templates sections,
// or we are using the managed runtime services fallback, which doesn't provide the
// file mapping feature (ex: older version of mrt100.dll, or no mrt100.dll at all).
// The only option is for the caller to attempt and recycle unused thunks to be able to
// find some free entries.
return(IntPtr.Zero);
}
// Each mapping consists of multiple blocks of thunk stubs/data pairs. Keep track of those
// so that we do not create a new mapping until all blocks in the sections we just mapped are consumed
IntPtr currentThunksBlock = nextThunksBlock;
for (int i = 0; i < Constants.NumThunkBlocksPerMapping; i++)
{
s_currentlyMappedThunkBlocks[i] = currentThunksBlock;
currentThunksBlock = InternalCalls.RhpGetNextThunkStubsBlockAddress(currentThunksBlock);
}
s_currentlyMappedThunkBlocksIndex = 1;
}
Debug.Assert(nextThunksBlock != IntPtr.Zero);
// Setup the thunks in the new block as a linked list of thunks.
// Use the first data field of the thunk to build the linked list.
IntPtr dataAddress = InternalCalls.RhpGetThunkDataBlockAddress(nextThunksBlock);
for (int i = 0; i < Constants.NumThunksPerBlock; i++)
{
if (i == (Constants.NumThunksPerBlock - 1))
{
*((IntPtr *)(dataAddress)) = IntPtr.Zero;
}
else
{
*((IntPtr *)(dataAddress)) = dataAddress + Constants.ThunkDataSize;
}
#if DEBUG
// Debug flag in the second data cell indicating the thunk is not used
*((IntPtr *)(dataAddress + IntPtr.Size)) = new IntPtr(-1);
#endif
dataAddress += Constants.ThunkDataSize;
}
return(nextThunksBlock);
}
// TODO: temporary to try things out, when working look to see how to refactor with FindFirstPassHandler
private static bool FindFirstPassHandlerWasm(object exception, uint idxStart, uint idxCurrentBlockStart /* the start IL idx of the current block for the landing pad, will use in place of PC */,
void *shadowStack, ref EHClauseIterator clauseIter, out uint tryRegionIdx, out byte *pHandler)
{
pHandler = (byte *)0;
tryRegionIdx = MaxTryRegionIdx;
uint lastTryStart = 0, lastTryEnd = 0;
RhEHClauseWasm ehClause = new RhEHClauseWasm();
for (uint curIdx = 0; clauseIter.Next(ref ehClause); curIdx++)
{
//
// Skip to the starting try region. This is used by collided unwinds and rethrows to pickup where
// the previous dispatch left off.
//
if (idxStart != MaxTryRegionIdx)
{
if (curIdx <= idxStart)
{
lastTryStart = ehClause._tryStartOffset;
lastTryEnd = ehClause._tryEndOffset;
continue;
}
// Now, we continue skipping while the try region is identical to the one that invoked the
// previous dispatch.
if ((ehClause._tryStartOffset == lastTryStart) && (ehClause._tryEndOffset == lastTryEnd))
{
continue;
}
// We are done skipping. This is required to handle empty finally block markers that are used
// to separate runs of different try blocks with same native code offsets.
idxStart = MaxTryRegionIdx;
}
EHClauseIterator.RhEHClauseKindWasm clauseKind = ehClause._clauseKind;
if (((clauseKind != EHClauseIterator.RhEHClauseKindWasm.RH_EH_CLAUSE_TYPED) &&
(clauseKind != EHClauseIterator.RhEHClauseKindWasm.RH_EH_CLAUSE_FILTER)) ||
!ehClause.ContainsCodeOffset(idxCurrentBlockStart))
{
continue;
}
// Found a containing clause. Because of the order of the clauses, we know this is the
// most containing.
if (clauseKind == EHClauseIterator.RhEHClauseKindWasm.RH_EH_CLAUSE_TYPED)
{
if (ShouldTypedClauseCatchThisException(exception, (EEType *)ehClause._typeSymbol))
{
pHandler = ehClause._handlerAddress;
tryRegionIdx = curIdx;
return(true);
}
}
else
{
tryRegionIdx = 0;
bool shouldInvokeHandler = InternalCalls.RhpCallFilterFunclet(exception, ehClause._filterAddress, shadowStack);
if (shouldInvokeHandler)
{
pHandler = ehClause._handlerAddress;
tryRegionIdx = curIdx;
return(true);
}
}
}
return(false);
}
internal static unsafe object GetCastableTargetIfPossible(ICastableObject castableObject, EEType *interfaceType, bool produceException, ref Exception exception)
{
CastableObjectCacheEntry <object>[] cache = Unsafe.As <CastableObject>(castableObject).Cache;
object targetObjectInitial = null;
if (cache != null)
{
targetObjectInitial = CacheLookup(cache, new IntPtr(interfaceType));
if (targetObjectInitial != null)
{
if (targetObjectInitial != s_castFailCanary)
{
return(targetObjectInitial);
}
else if (!produceException)
{
return(null);
}
}
}
// Call into the object to determine if the runtime can perform the cast. This will return null if it fails.
object targetObject = castableObject.CastToInterface(new EETypePtr(new IntPtr(interfaceType)), produceException, out exception);
// If the target object is null, and that result has already been cached, just return null now.
// Otherwise, we need to store the canary in the cache so future failing "is" checks can be fast
if (targetObject == null)
{
if (targetObjectInitial != null)
{
return(null);
}
else
{
targetObject = s_castFailCanary;
}
}
InternalCalls.RhpAcquireCastCacheLock();
// Assuming we reach here, we should attempt to add the newly discovered targetObject to the per-object cache
// First, check to see if something is already there
// we may have replaced the cache object since the earlier acquisition in this method. Re-acquire the cache object
// here.
cache = Unsafe.As <CastableObject>(castableObject).Cache;
object targetObjectInCache = null;
if (cache != null)
{
targetObjectInCache = CacheLookup(cache, new IntPtr(interfaceType));
}
if (targetObjectInCache == null)
{
// If the target object still isn't in the cache by this point, add it now
AddToCastableCache(castableObject, interfaceType, targetObject);
targetObjectInCache = targetObject;
}
InternalCalls.RhpReleaseCastCacheLock();
if (targetObjectInCache != s_castFailCanary)
{
return(targetObjectInCache);
}
else
{
return(null);
}
}
internal bool Next(out uint uExCollideClauseIdx, out bool fUnwoundReversePInvoke)
{
return(InternalCalls.RhpSfiNext(ref this, out uExCollideClauseIdx, out fUnwoundReversePInvoke));
}
private static unsafe IntPtr RhResolveDispatchWorker(object pObject, void *cell, ref DispatchCellInfo cellInfo)
{
// Type of object we're dispatching on.
EEType *pInstanceType = pObject.EEType;
if (cellInfo.CellType == DispatchCellType.InterfaceAndSlot)
{
// Type whose DispatchMap is used. Usually the same as the above but for types which implement ICastable
// we may repeat this process with an alternate type.
EEType *pResolvingInstanceType = pInstanceType;
IntPtr pTargetCode = DispatchResolve.FindInterfaceMethodImplementationTarget(pResolvingInstanceType,
cellInfo.InterfaceType.ToPointer(),
cellInfo.InterfaceSlot);
if (pTargetCode == IntPtr.Zero && pInstanceType->IsICastable)
{
// TODO!! BEGIN REMOVE THIS CODE WHEN WE REMOVE ICASTABLE
// Dispatch not resolved through normal dispatch map, try using the ICastable
// Call the ICastable.IsInstanceOfInterface method directly rather than via an interface
// dispatch since we know the method address statically. We ignore any cast error exception
// object passed back on failure (result == false) since IsInstanceOfInterface never throws.
IntPtr pfnIsInstanceOfInterface = pInstanceType->ICastableIsInstanceOfInterfaceMethod;
Exception castError = null;
if (CalliIntrinsics.Call <bool>(pfnIsInstanceOfInterface, pObject, cellInfo.InterfaceType.ToPointer(), out castError))
{
IntPtr pfnGetImplTypeMethod = pInstanceType->ICastableGetImplTypeMethod;
pResolvingInstanceType = (EEType *)CalliIntrinsics.Call <IntPtr>(pfnGetImplTypeMethod, pObject, new IntPtr(cellInfo.InterfaceType.ToPointer()));
pTargetCode = DispatchResolve.FindInterfaceMethodImplementationTarget(pResolvingInstanceType,
cellInfo.InterfaceType.ToPointer(),
cellInfo.InterfaceSlot);
}
else
// TODO!! END REMOVE THIS CODE WHEN WE REMOVE ICASTABLE
{
// Dispatch not resolved through normal dispatch map, using the CastableObject path
pTargetCode = InternalCalls.RhpGetCastableObjectDispatchHelper();
}
}
return(pTargetCode);
}
else if (cellInfo.CellType == DispatchCellType.VTableOffset)
{
// Dereference VTable
return(*(IntPtr *)(((byte *)pInstanceType) + cellInfo.VTableOffset));
}
else
{
#if SUPPORTS_NATIVE_METADATA_TYPE_LOADING_AND_SUPPORTS_TOKEN_BASED_DISPATCH_CELLS
// Attempt to convert dispatch cell to non-metadata form if we haven't acquired a cache for this cell yet
if (cellInfo.HasCache == 0)
{
cellInfo = InternalTypeLoaderCalls.ConvertMetadataTokenDispatch(InternalCalls.RhGetModuleFromPointer(cell), cellInfo);
if (cellInfo.CellType != DispatchCellType.MetadataToken)
{
return(RhResolveDispatchWorker(pObject, cell, ref cellInfo));
}
}
// If that failed, go down the metadata resolution path
return(InternalTypeLoaderCalls.ResolveMetadataTokenDispatch(InternalCalls.RhGetModuleFromPointer(cell), (int)cellInfo.MetadataToken, new IntPtr(pInstanceType)));
#else
EH.FallbackFailFast(RhFailFastReason.InternalError, null);
return(IntPtr.Zero);
#endif
}
}
internal bool Init(EH.PAL_LIMITED_CONTEXT *pStackwalkCtx, bool instructionFault = false)
{
return(InternalCalls.RhpSfiInit(ref this, pStackwalkCtx, instructionFault));
}
// This is a fail-fast function used by the runtime as a last resort that will terminate the process with
// as little effort as possible. No guarantee is made about the semantics of this fail-fast.
internal static void FallbackFailFast(RhFailFastReason reason, object unhandledException)
{
InternalCalls.RhpFallbackFailFast();
}
internal bool Next(uint *uExCollideClauseIdx, bool *fUnwoundReversePInvoke)
{
return(InternalCalls.RhpSfiNext(ref this, uExCollideClauseIdx, fUnwoundReversePInvoke));
}
private static bool FindFirstPassHandler(object exception, uint idxStart,
ref StackFrameIterator frameIter, out uint tryRegionIdx, out byte *pHandler)
{
pHandler = null;
tryRegionIdx = MaxTryRegionIdx;
EHEnum ehEnum;
byte * pbMethodStartAddress;
if (!InternalCalls.RhpEHEnumInitFromStackFrameIterator(ref frameIter, &pbMethodStartAddress, &ehEnum))
{
return(false);
}
byte *pbControlPC = frameIter.ControlPC;
uint codeOffset = (uint)(pbControlPC - pbMethodStartAddress);
uint lastTryStart = 0, lastTryEnd = 0;
// Search the clauses for one that contains the current offset.
RhEHClause ehClause;
for (uint curIdx = 0; InternalCalls.RhpEHEnumNext(&ehEnum, &ehClause); curIdx++)
{
//
// Skip to the starting try region. This is used by collided unwinds and rethrows to pickup where
// the previous dispatch left off.
//
if (idxStart != MaxTryRegionIdx)
{
if (curIdx <= idxStart)
{
lastTryStart = ehClause._tryStartOffset; lastTryEnd = ehClause._tryEndOffset;
continue;
}
// Now, we continue skipping while the try region is identical to the one that invoked the
// previous dispatch.
if ((ehClause._tryStartOffset == lastTryStart) && (ehClause._tryEndOffset == lastTryEnd))
{
continue;
}
// We are done skipping. This is required to handle empty finally block markers that are used
// to separate runs of different try blocks with same native code offsets.
idxStart = MaxTryRegionIdx;
}
RhEHClauseKind clauseKind = ehClause._clauseKind;
if (((clauseKind != RhEHClauseKind.RH_EH_CLAUSE_TYPED) &&
(clauseKind != RhEHClauseKind.RH_EH_CLAUSE_FILTER)) ||
!ehClause.ContainsCodeOffset(codeOffset))
{
continue;
}
// Found a containing clause. Because of the order of the clauses, we know this is the
// most containing.
if (clauseKind == RhEHClauseKind.RH_EH_CLAUSE_TYPED)
{
if (ShouldTypedClauseCatchThisException(exception, (EEType *)ehClause._pTargetType))
{
pHandler = ehClause._handlerAddress;
tryRegionIdx = curIdx;
return(true);
}
}
else
{
byte *pFilterFunclet = ehClause._filterAddress;
bool shouldInvokeHandler =
InternalCalls.RhpCallFilterFunclet(exception, pFilterFunclet, frameIter.RegisterSet);
if (shouldInvokeHandler)
{
pHandler = ehClause._handlerAddress;
tryRegionIdx = curIdx;
return(true);
}
}
}
return(false);
}
internal bool Init(EH.PAL_LIMITED_CONTEXT *pStackwalkCtx)
{
return(InternalCalls.RhpSfiInit(ref this, pStackwalkCtx));
}
