/// <summary>
/// Begins a catch block for the given exception type in the given exception block.
///
/// The given exception block must still be open.
/// </summary>
public CatchBlock BeginCatchBlock(ExceptionBlock forTry, Type exceptionType)
{
if (exceptionType == null)
{
throw new ArgumentNullException("exceptionType");
}
if (forTry == null)
{
throw new ArgumentNullException("forTry");
}
if (((IOwned)forTry).Owner != this)
{
FailOwnership(forTry);
}
if (CurrentExceptionBlock.Count > 0 && forTry != CurrentExceptionBlock.Peek())
{
throw new InvalidOperationException("Cannot start CatchBlock on " + forTry + " while inner ExceptionBlock is still open");
}
if (!typeof(Exception).IsAssignableFrom(exceptionType))
{
throw new ArgumentException("BeginCatchBlock expects a type descending from Exception, found " + exceptionType, "exceptionType");
}
var currentlyOpen = CatchBlocks.Where(c => c.Key.ExceptionBlock == forTry && c.Value.Item2 == -1).Select(s => s.Key).SingleOrDefault();
if (currentlyOpen != null)
{
throw new InvalidOperationException("Cannot start a new catch block, " + currentlyOpen + " has not been ended");
}
if (MustMark)
{
MarkLabel(DefineLabel(AutoNamer.Next(this, "__autolabel")));
}
UpdateState(Wrap(new[] { new StackTransition(0) }, "BeginCatchBlock"));
var tryBlock = TryBlocks[forTry];
if (tryBlock.Item2 != -1)
{
throw new SigilVerificationException("BeginCatchBlock expects an unclosed exception block, but " + forTry + " is already closed", IL.Instructions(AllLocals));
}
IL.BeginCatchBlock(exceptionType);
UpdateState(Wrap(StackTransition.Push(exceptionType), "BeginCatchBlock"));
var ret = new CatchBlock(exceptionType, forTry);
CatchBlocks[ret] = SigilTuple.Create(IL.Index, -1);
return(ret);
}
/// <summary>
/// Begins a finally block on the given exception block.
///
/// Only one finally block can be defined per exception block, and the block cannot appear within a catch block.
///
/// The given exception block must still be open.
/// </summary>
public FinallyBlock BeginFinallyBlock(ExceptionBlock forTry)
{
if (forTry == null)
{
throw new ArgumentNullException("forTry");
}
if (((IOwned)forTry).Owner != this)
{
FailOwnership(forTry);
}
var tryBlock = TryBlocks[forTry];
if (tryBlock.Item2 != -1)
{
throw new InvalidOperationException("BeginFinallyBlock expects an unclosed exception block, but " + forTry + " is already closed");
}
if (CurrentExceptionBlock.Count > 0 && forTry != CurrentExceptionBlock.Peek())
{
throw new InvalidOperationException("Cannot begin FinallyBlock on " + forTry + " while inner ExceptionBlock " + CurrentExceptionBlock.Peek() + " is still open");
}
if (FinallyBlocks.Any(kv => kv.Key.ExceptionBlock == forTry))
{
throw new InvalidOperationException("There can only be one finally block per ExceptionBlock, and one is already defined for " + forTry);
}
if (MustMark)
{
MarkLabel(DefineLabel(AutoNamer.Next(this, "__autolabel")));
}
UpdateState(Wrap(new[] { new StackTransition(0) }, "BeginFinallyBlock"));
var ret = new FinallyBlock(forTry);
IL.BeginFinallyBlock();
FinallyBlocks[ret] = SigilTuple.Create(IL.Index, -1);
return(ret);
}
/// <summary>
/// Start a new exception block. This is roughly analogous to a `try` block in C#, but an exception block contains it's catch and finally blocks.
/// </summary>
public ExceptionBlock BeginExceptionBlock()
{
if (MustMark)
{
MarkLabel(DefineLabel(AutoNamer.Next(this, "__autolabel")));
}
UpdateState(Wrap(new[] { new StackTransition(0) }, "BeginExceptionBlock"));
var labelDel = IL.BeginExceptionBlock();
var label = new Label(this, labelDel, AutoNamer.Next(this, "__exceptionBlockEnd"));
CurrentLabels[label.Name] = label;
var ret = new ExceptionBlock(label);
TryBlocks[ret] = SigilTuple.Create(IL.Index, -1);
CurrentExceptionBlock.Push(ret);
return(ret);
}
/// <summary>
/// Ends the given exception block.
///
/// All catch and finally blocks associated with the given exception block must be ended before this method is called.
/// </summary>
public Emit <DelegateType> EndExceptionBlock(ExceptionBlock forTry)
{
if (forTry == null)
{
throw new ArgumentNullException("forTry");
}
if (((IOwned)forTry).Owner != this)
{
FailOwnership(forTry);
}
var location = TryBlocks[forTry];
// Can't close the same exception block twice
if (location.Item2 != -1)
{
throw new InvalidOperationException("ExceptionBlock has already been ended");
}
if (CurrentExceptionBlock.Count > 0 && forTry != CurrentExceptionBlock.Peek())
{
throw new InvalidOperationException("Cannot end outer ExceptionBlock " + forTry + " while inner EmitExceptionBlock " + CurrentExceptionBlock.Peek() + " is open");
}
// Can't close an exception block while there are outstanding catch blocks
foreach (var kv in CatchBlocks.AsEnumerable())
{
if (kv.Key.ExceptionBlock != forTry)
{
continue;
}
if (kv.Value.Item2 == -1)
{
throw new InvalidOperationException("Cannot end ExceptionBlock, CatchBlock " + kv.Key + " has not been ended");
}
}
foreach (var kv in FinallyBlocks.AsEnumerable())
{
if (kv.Key.ExceptionBlock != forTry)
{
continue;
}
if (kv.Value.Item2 == -1)
{
throw new InvalidOperationException("Cannot end ExceptionBlock, FinallyBlock " + kv.Key + " has not been ended");
}
}
if (!CatchBlocks.Any(k => k.Key.ExceptionBlock == forTry) && !FinallyBlocks.Any(k => k.Key.ExceptionBlock == forTry))
{
throw new InvalidOperationException("Cannot end ExceptionBlock without defining at least one of a catch or finally block");
}
IL.EndExceptionBlock();
TryBlocks[forTry] = SigilTuple.Create(location.Item1, IL.Index);
Marks[forTry.Label] = IL.Index;
CurrentExceptionBlock.Pop();
if (MustMark)
{
MarkLabel(DefineLabel(AutoNamer.Next(this, "__autolabel")));
}
return(this);
}
