void EmitUsing(LocalBuilder local, System.Action body)
{
var endFinally = IL.DefineLabel();
IL.BeginExceptionBlock();
body();
IL.BeginFinallyBlock();
IL.Emit(OpCodes.Ldloc, local);
IL.Emit(OpCodes.Ldnull);
IL.Emit(OpCodes.Beq, endFinally);
IL.Emit(OpCodes.Ldloc, local);
IL.Emit(OpCodes.Callvirt, typeof(IDisposable).GetMethod("Dispose"));
IL.MarkLabel(endFinally);
IL.EndExceptionBlock();
}
/// <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);
}
public override void Emit( )
{
tryLabel = IL.BeginExceptionBlock();
}
private void EmitTryExpression(Expression expr)
{
var node = (TryExpression)expr;
CheckTry();
//******************************************************************
// 1. ENTERING TRY
//******************************************************************
PushLabelBlock(LabelScopeKind.Try);
IL.BeginExceptionBlock();
//******************************************************************
// 2. Emit the try statement body
//******************************************************************
EmitExpression(node.Body);
var tryType = node.Type;
LocalBuilder value = null;
if (tryType != typeof(void))
{
//store the value of the try body
value = GetLocal(tryType);
IL.Emit(OpCodes.Stloc, value);
}
//******************************************************************
// 3. Emit the catch blocks
//******************************************************************
foreach (var cb in node.Handlers)
{
PushLabelBlock(LabelScopeKind.Catch);
// Begin the strongly typed exception block
if (cb.Filter == null)
{
IL.BeginCatchBlock(cb.Test);
}
else
{
IL.BeginExceptFilterBlock();
}
EnterScope(cb);
EmitCatchStart(cb);
//
// Emit the catch block body
//
EmitExpression(cb.Body);
if (tryType != typeof(void))
{
//store the value of the catch block body
// ReSharper disable once AssignNullToNotNullAttribute
IL.Emit(OpCodes.Stloc, value);
}
ExitScope(cb);
PopLabelBlock(LabelScopeKind.Catch);
}
//******************************************************************
// 4. Emit the finally block
//******************************************************************
if (node.Finally != null || node.Fault != null)
{
PushLabelBlock(LabelScopeKind.Finally);
if (node.Finally != null)
{
IL.BeginFinallyBlock();
}
else
{
IL.BeginFaultBlock();
}
// Emit the body
EmitExpressionAsVoid(node.Finally ?? node.Fault);
IL.EndExceptionBlock();
PopLabelBlock(LabelScopeKind.Finally);
}
else
{
IL.EndExceptionBlock();
}
if (tryType != typeof(void))
{
// ReSharper disable once AssignNullToNotNullAttribute
IL.Emit(OpCodes.Ldloc, value);
FreeLocal(value);
}
PopLabelBlock(LabelScopeKind.Try);
}
private void Try()
{
IL.BeginExceptionBlock(); // try {
}
private void EmitTryExpression(Expression expr)
{
var node = (TryExpression)expr;
CheckTry(_labelBlock);
//******************************************************************
// 1. ENTERING TRY
//******************************************************************
var parent = _labelBlock;
_labelBlock = new LabelScopeInfo(parent, LabelScopeKind.Try);
IL.BeginExceptionBlock();
//******************************************************************
// 2. Emit the try statement body
//******************************************************************
EmitExpression(node.Body);
var tryType = node.Type;
LocalBuilder?value = null;
if (tryType != typeof(void))
{
//store the value of the try body
value = GetLocal(tryType);
IL.Emit(OpCodes.Stloc, value);
}
//******************************************************************
// 3. Emit the catch blocks
//******************************************************************
foreach (var cb in node.Handlers)
{
var tmpParent = _labelBlock;
_labelBlock = new LabelScopeInfo(tmpParent, LabelScopeKind.Catch);
// Begin the strongly typed exception block
if (cb.Filter == null)
{
IL.BeginCatchBlock(cb.Test);
}
else
{
IL.BeginExceptFilterBlock();
}
var innerScopeInfo = GetInnerScope(node, _scope);
if (innerScopeInfo.HasValue)
{
_scope = innerScopeInfo.Value.child.Enter(this, innerScopeInfo.Value.parent);
}
EmitCatchStart(cb);
//
// Emit the catch block body
//
EmitExpression(cb.Body);
if (tryType != typeof(void))
{
//store the value of the catch block body
// ReSharper disable once AssignNullToNotNullAttribute
IL.Emit(OpCodes.Stloc, value);
}
if (innerScopeInfo.HasValue)
{
innerScopeInfo.Value.child.Exit();
_scope = innerScopeInfo.Value.parent;
}
_labelBlock = tmpParent;
}
//******************************************************************
// 4. Emit the finally block
//******************************************************************
if (node.Finally != null || node.Fault != null)
{
var tmpParent = _labelBlock;
_labelBlock = new LabelScopeInfo(tmpParent, LabelScopeKind.Finally);
if (node.Finally != null)
{
IL.BeginFinallyBlock();
}
else
{
IL.BeginFaultBlock();
}
// Emit the body
EmitExpressionAsVoid(node.Finally ?? node.Fault !);
IL.EndExceptionBlock();
_labelBlock = tmpParent;
}
else
{
IL.EndExceptionBlock();
}
if (value != null)
{
// ReSharper disable once AssignNullToNotNullAttribute
IL.Emit(OpCodes.Ldloc, value);
FreeLocal(value);
}
_labelBlock = parent;
}
