/// <summary>
/// Adds catch region.
/// </summary>
/// <param name="tryStart">Label marking the first instruction of the try block.</param>
/// <param name="tryEnd">Label marking the instruction immediately following the try block.</param>
/// <param name="handlerStart">Label marking the first instruction of the handler.</param>
/// <param name="handlerEnd">Label marking the instruction immediately following the handler.</param>
/// <param name="catchType">The type of exception to be caught: <see cref="TypeDefinitionHandle"/>, <see cref="TypeReferenceHandle"/> or <see cref="TypeSpecificationHandle"/>.</param>
/// <exception cref="ArgumentException">A label was not defined by an instruction encoder this builder is associated with.</exception>
/// <exception cref="ArgumentException"><paramref name="catchType"/> is not a valid type handle.</exception>
/// <exception cref="ArgumentNullException">A label has default value.</exception>
public void AddCatchRegion(LabelHandle tryStart, LabelHandle tryEnd, LabelHandle handlerStart, LabelHandle handlerEnd, EntityHandle catchType)
{
if (!ExceptionRegionEncoder.IsValidCatchTypeHandle(catchType))
{
Throw.InvalidArgument_Handle(nameof(catchType));
}
AddExceptionRegion(ExceptionRegionKind.Catch, tryStart, tryEnd, handlerStart, handlerEnd, catchType: catchType);
}
internal void SerializeExceptionTable(BlobBuilder builder)
{
if (_lazyExceptionHandlers == null || _lazyExceptionHandlers.Count == 0)
{
return;
}
var regionEncoder = ExceptionRegionEncoder.SerializeTableHeader(builder, _lazyExceptionHandlers.Count, HasSmallExceptionRegions());
foreach (var handler in _lazyExceptionHandlers)
{
// Note that labels have been validated when added to the handler list,
// they might not have been marked though.
int tryStart = GetLabelOffsetChecked(handler.TryStart);
int tryEnd = GetLabelOffsetChecked(handler.TryEnd);
int handlerStart = GetLabelOffsetChecked(handler.HandlerStart);
int handlerEnd = GetLabelOffsetChecked(handler.HandlerEnd);
if (tryStart > tryEnd)
{
Throw.InvalidOperation(SR.Format(SR.InvalidExceptionRegionBounds, tryStart, tryEnd));
}
if (handlerStart > handlerEnd)
{
Throw.InvalidOperation(SR.Format(SR.InvalidExceptionRegionBounds, handlerStart, handlerEnd));
}
int catchTokenOrOffset;
switch (handler.Kind)
{
case ExceptionRegionKind.Catch:
catchTokenOrOffset = MetadataTokens.GetToken(handler.CatchType);
break;
case ExceptionRegionKind.Filter:
catchTokenOrOffset = GetLabelOffsetChecked(handler.FilterStart);
break;
default:
catchTokenOrOffset = 0;
break;
}
regionEncoder.AddUnchecked(
handler.Kind,
tryStart,
tryEnd - tryStart,
handlerStart,
handlerEnd - handlerStart,
catchTokenOrOffset);
}
}
private bool HasSmallExceptionRegions()
{
Debug.Assert(_lazyExceptionHandlers != null);
if (!ExceptionRegionEncoder.IsSmallRegionCount(_lazyExceptionHandlers.Count))
{
return(false);
}
foreach (var handler in _lazyExceptionHandlers)
{
if (!ExceptionRegionEncoder.IsSmallExceptionRegionFromBounds(GetLabelOffsetChecked(handler.TryStart), GetLabelOffsetChecked(handler.TryEnd)) ||
!ExceptionRegionEncoder.IsSmallExceptionRegionFromBounds(GetLabelOffsetChecked(handler.HandlerStart), GetLabelOffsetChecked(handler.HandlerEnd)))
{
return(false);
}
}
return(true);
}
