public virtual void VisitExpressionBlock(BoundExpressionBlock node)
{
DefaultVisit(node);
}
public override void VisitExpressionBlock(BoundExpressionBlock node)
{
base.VisitExpressionBlock(node);
MarkRead(node.Result);
}
public override void VisitExpressionBlock(BoundExpressionBlock node)
{
base.VisitExpressionBlock(node);
// The BuildingVisitor only allows temporaries to be put into
// the result of the expression block. In the Squelch
// phase, we're relaxing this requirement, but we can
// safely cast here.
MarkRead((BoundTemporary)node.Result);
}
public override BoundNode VisitExpressionBlock(BoundExpressionBlock node)
{
// Check for expression squelching. We can only squelch an
// expression if it's the only thing in the expression block.
// If this is the case, just skip over the whole algorithm and
// return the expression.
var resultStatistic = _statistics[(BoundTemporary)node.Result];
if (node.Body.Nodes.Count == 1 && resultStatistic.WriteState == WriteType.Expression)
return resultStatistic.Value.Expression.Accept(this);
// If we can't squelch the whole expression, we also cannot
// squelch the result temporary if it isn't a local.
// We for the write state to other to indicate this.
if (resultStatistic.ShouldRemove && resultStatistic.WriteState != WriteType.Local)
resultStatistic.WriteState = WriteType.DoNotRemove;
// Rewrite the body.
var body = (BoundBlock)Visit(node.Body);
// Check whether the result must be updated.
IBoundReadable result;
if (resultStatistic.ShouldReplace)
{
// We should only get locals here, because the result counts
// as a read and there should also be a read in the expression
// block.
Debug.Assert(resultStatistic.WriteState == WriteType.Local);
result = ((BoundGetVariable)resultStatistic.Value.Expression).Variable;
}
else
{
result = node.Result;
}
return node.Update(result, body);
}
private BoundValueType EmitExpressionBlock(BoundExpressionBlock node)
{
EmitStatement(node.Body);
EmitGetVariable(node.Result);
return node.ValueType;
}
