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;
}
}
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);
}
// 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 idxTryLandingStart /* the start IL idx of the try region for the landing pad, will use in place of PC */,
void *shadowStack, void *exInfo,
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.TryStartsAt(idxTryLandingStart))
{
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);
}