/// <summary>
/// Starts a new catch block which handles exceptions of the given type based on the filter created by the given action
/// </summary>
/// <param name="exceptionType">The type of exception this catch block should handle</param>
/// <param name="filter">An action that writes the IL comprising the filter block</param>
public CatchBlock CatchBlock(Type exceptionType, Action <XsILGenerator> filter)
{
EnsureTryBlockEnded();
if (hasFinallyBlock)
{
throw new InvalidOperationException(
"Exception block already has a finally block - cannot start new catch block");
}
if (hasFaultBlock)
{
throw new InvalidOperationException(
"Exception block already has a fault block - cannot have both catch and fault blocks");
}
if (filter != null)
{
generator.BeginExceptFilterBlock();
if (exceptionType != null)
{
var filterBlockEnd = generator.DefineLabel();
var customFilter = generator.DefineLabel();
generator
.Duplicate()
.IsInstanceOfType(exceptionType)
.BranchIfTrue(customFilter)
.Pop()
.LoadConstant(false)
.BranchTo(filterBlockEnd);
generator.MarkLabel(customFilter);
filter(generator);
generator.MarkLabel(filterBlockEnd);
}
else
{
filter(generator);
}
generator.BeginCatchBlock(null);
}
else
{
generator.BeginCatchBlock(exceptionType);
}
hasCatchBlocks = true;
return(new CatchBlock(generator, endLabel));
}
internal static Label GetOrCreateLabel(this XsILGenerator generator, string labelName)
{
var data = GeneratorExtraData.GetOrCreateValue(generator);
Label label;
if (data.Labels.TryGetValue(labelName, out label))
{
return(label);
}
else
{
label = generator.DefineLabel();
data.Labels.Add(labelName, label);
return(label);
}
}
internal ExceptionBlock(XsILGenerator generator)
{
this.generator = generator;
endLabel = generator.DefineLabel();
generator.BeginExceptionBlock();
}
