protected override Expression VisitGoto(GotoExpression node)
{
BranchLabel label;
var target = node.Target;
var value = Visit(node.Value);
// TODO: Is it possible for an inner reducible node of the loop to rely on nodes produced by reducing outer reducible nodes?
// Unknown label => must be within the loop:
if (!_labelMapping.TryGetValue(target, out label))
{
return(node.Update(target, value));
}
// Known label within the loop:
if (label.TargetIndex >= _loopStartInstructionIndex && label.TargetIndex < _loopEndInstructionIndex)
{
return(node.Update(target, value));
}
return(Expression.Return(_returnLabel,
(value != null) ?
Expression.Call(_frameVar, InterpretedFrame.GotoMethod, Expression.Constant(label.LabelIndex), AstUtils.Box(value)) :
Expression.Call(_frameVar, InterpretedFrame.VoidGotoMethod, Expression.Constant(label.LabelIndex)),
node.Type
));
}
protected override Expression VisitGoto(GotoExpression node)
{
if (node.Target.Name == "Break")
{
return(node.Update(BreakTarget, null));
}
else if (node.Target.Name == "Continue")
{
return(node.Update(ContinueTarget, null));
}
return(base.VisitGoto(node));
}
public void UpdateDifferentTargetIsDifferent()
{
Expression value = Expression.Constant(0);
GotoExpression ret = Expression.Break(Expression.Label(typeof(int)), value);
Assert.NotSame(ret, ret.Update(Expression.Label(typeof(int)), value));
}
public void UpdateDiferentValueIsDifferent()
{
LabelTarget target = Expression.Label(typeof(int));
GotoExpression ret = Expression.Break(target, Expression.Constant(0));
Assert.NotSame(ret, ret.Update(target, Expression.Constant(0)));
}
protected override Expression VisitGoto(GotoExpression node)
{
BranchLabel label;
LabelTarget key = node.Target;
Expression expression = this.Visit(node.Value);
if (!this._labelMapping.TryGetValue(key, out label))
{
return(node.Update(key, expression));
}
if ((label.TargetIndex >= this._loopStartInstructionIndex) && (label.TargetIndex < this._loopEndInstructionIndex))
{
return(node.Update(key, expression));
}
return(Expression.Return(this._returnLabel, ((expression != null) && (expression.Type != typeof(void))) ? Expression.Call(this._frameVar, InterpretedFrame.GotoMethod, Expression.Constant(label.LabelIndex), Utils.Box(expression)) : Expression.Call(this._frameVar, InterpretedFrame.VoidGotoMethod, new Expression[] { Expression.Constant(label.LabelIndex) }), node.Type));
}
public void UpdateSameIsSame()
{
LabelTarget target = Expression.Label(typeof(int));
Expression value = Expression.Constant(0);
GotoExpression ret = Expression.Goto(target, value);
Assert.Same(ret, ret.Update(target, value));
}
public void UpdateSameIsSame()
{
LabelTarget target = Expression.Label(typeof(int));
Expression value = Expression.Constant(0);
GotoExpression ret = Expression.Break(target, value);
Assert.Same(ret, ret.Update(target, value));
Assert.Same(ret, NoOpVisitor.Instance.Visit(ret));
}
protected override Expression VisitGoto(GotoExpression node)
{
var constant = node.Value as ConstantExpression;
Expression value = _defaultValue;
if (constant != null && (bool)constant.Value)
{
value = _ifTure;
}
return(node.Update(this.VisitLabelTarget(node.Target), value));
}
public T?Simplify <T>(T?expression) where T : Expression
{
if (expression is null)
{
return(null);
}
Expression expr = expression.Reduce() switch
{
UnaryExpression unaryExpr => unaryExpr.Update(Simplify(unaryExpr.Operand)),
BinaryExpression binaryExpr => binaryExpr.Update(Simplify(binaryExpr.Left), binaryExpr.Conversion, Simplify(binaryExpr.Right)),
LambdaExpression lambdaExpr => Expression.Lambda(Simplify(lambdaExpr.Body), lambdaExpr.Name, lambdaExpr.TailCall, Simplify(lambdaExpr.Parameters)),
TryExpression tryExpr => tryExpr.Update(Simplify(tryExpr.Body), Simplify(tryExpr.Handlers), Simplify(tryExpr.Finally), Simplify(tryExpr.Fault)),
NewExpression newExpr => newExpr.Update(Simplify(newExpr.Arguments)),
GotoExpression gotoExpr => gotoExpr.Update(gotoExpr.Target, Simplify(gotoExpr.Value)),
LoopExpression loopExpr => loopExpr.Update(loopExpr.BreakLabel, loopExpr.ContinueLabel, Simplify(loopExpr.Body)),
BlockExpression blockExpr => blockExpr.Update(Simplify(blockExpr.Variables), Simplify(blockExpr.Expressions)),
IndexExpression indexExpr => indexExpr.Update(Simplify(indexExpr.Object) !, Simplify(indexExpr.Arguments)),
LabelExpression labelExpr => labelExpr.Update(labelExpr.Target, Simplify(labelExpr.DefaultValue)),
MemberExpression memberExpr => memberExpr.Update(Simplify(memberExpr.Expression)),
SwitchExpression switchExpr => switchExpr.Update(Simplify(switchExpr.SwitchValue), Simplify(switchExpr.Cases), Simplify(switchExpr.DefaultBody)),
DynamicExpression dynamicExpr => dynamicExpr.Update(Simplify(dynamicExpr.Arguments)),
ListInitExpression listInitExpr => listInitExpr.Update(Simplify(listInitExpr.NewExpression), Simplify(listInitExpr.Initializers)),
NewArrayExpression newArrayExpr => newArrayExpr.Update(Simplify(newArrayExpr.Expressions)),
InvocationExpression invokeExpr => invokeExpr.Update(Simplify(invokeExpr.Expression), Simplify(invokeExpr.Arguments)),
MemberInitExpression memberInitExpr => memberInitExpr.Update(Simplify(memberInitExpr.NewExpression), memberInitExpr.Bindings),
MethodCallExpression methodCallExpr => methodCallExpr.Update(Simplify(methodCallExpr.Object), Simplify(methodCallExpr.Arguments)),
TypeBinaryExpression typeBinaryExpr => typeBinaryExpr.Update(Simplify(typeBinaryExpr.Expression)),
ConditionalExpression condExpr => condExpr.Update(Simplify(condExpr.Test), Simplify(condExpr.IfTrue), Simplify(condExpr.IfFalse)),
RuntimeVariablesExpression runtimeVarExpr => runtimeVarExpr.Update(Simplify(runtimeVarExpr.Variables)),
_ => expression
};
foreach (var transform in transformers)
{
expr = transform.Transform(expr, this);
}
return((T)expr);
}
/// <summary>
/// Visits the children of the <see cref="GotoExpression" />.
/// </summary>
/// <param name="node">The expression to visit.</param>
/// <returns>The modified expression, if it or any subexpression was modified;
/// otherwise, returns the original expression.</returns>
protected internal virtual Expression VisitGoto(GotoExpression node)
{
return(node.Update(VisitLabelTarget(node.Target), Visit(node.Value)));
}
private static Expression SetChildren(ReadOnlySpan <Expression> newChildren, GotoExpression g) => g.Update(g.Target, g.Value == null ? null : newChildren[0]);
/// <summary>
/// Visits the children of the <see cref="GotoExpression"/>.
/// </summary>
/// <param name="node">The expression to visit.</param>
/// <returns>The modified expression, if it or any subexpression was modified;
/// otherwise, returns the original expression.</returns>
protected override Expression VisitGoto(GotoExpression node)
{
return(node.Update(VisitLabelTarget(node.Target), Visit(node.Value)));
}
protected virtual Expression VisitGoto(GotoExpression node, Type expectedType) => node.Update(VisitLabelTarget(node.Target, expectedType), Visit(node.Value, node.Target.Type == typeof(void) ? null : node.Target.Type));