/// <summary>
/// If supplied expression is of Nullable(T) type, invokes its GetValueOrDefault method.
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
public static Expression RemoveNullability(this Expression expression)
{
return
(expression.IsVoid()
? expression
: expression.IsNullableType()
? ConstantHelper.TryEvalConst(null, expression.Type.GetField("Value"), expression)
: expression);
}
private static bool TryAdjustNumericType(ParseTreeNode root, Expression expr, Type targetType, out Expression adjusted)
{
if (expr.IsNumeric() && Numerics.Contains(targetType))
{
var mySize = Marshal.SizeOf(expr.Type);
var targetSize = Marshal.SizeOf(targetType);
if (mySize < targetSize)
{
adjusted = ConstantHelper.TryEvalConst(root, expr, ExpressionType.Convert, targetType);
return(true);
}
if (mySize == targetSize)
{
if (ReferenceEquals(targetType, typeof(Single)) ||
ReferenceEquals(targetType, typeof(Double)))
{
adjusted = ConstantHelper.TryEvalConst(root, expr, ExpressionType.Convert, targetType);
return(true);
}
}
// attempt overflow-checked autocast between integer constants,
// or from integer to real constants (but never from reals to integers)
if (!expr.IsRealNumeric() || !targetType.IsInteger())
{
// only attempt to auto-convert constants
var constExpr = expr as ConstantExpression;
if (constExpr != null)
{
try
{
adjusted = ConstantHelper.EvalConst(root, constExpr, ExpressionType.ConvertChecked, targetType);
return(true);
}
catch (Exception e)
{
if (!(e is TargetInvocationException || e is OverflowException))
{
// something unexpected happened
throw;
}
// we'll get here if a conversion to target type causes overflow
}
}
}
}
adjusted = null;
return(false);
}
/// <summary>
/// Attempts to auto-adjust the size of arguments for a binary arithmetic operation.
/// Integers grow up to Int64, Double or Decimal, floats grow up to Decimal.
/// </summary>
/// <param name="leftExpr">Left argument</param>
/// <param name="rightExpr">Right argument</param>
/// <param name="root">Corresponding parse tree node</param>
/// <exception cref="ArgumentNullException"><paramref name="root"/> is null</exception>
/// <exception cref="ArgumentNullException"><paramref name="leftExpr"/> is null</exception>
/// <exception cref="ArgumentNullException"><paramref name="rightExpr"/> is null</exception>
/// <exception cref="CompilationException">Argument types cannot be adjusted, try conversion</exception>
public static void AdjustArgumentsForBinaryOperation(ref Expression leftExpr, ref Expression rightExpr, ParseTreeNode root)
{
if (root == null)
{
throw new ArgumentNullException("root");
}
if (leftExpr == null)
{
throw new ArgumentNullException("leftExpr");
}
if (rightExpr == null)
{
throw new ArgumentNullException("rightExpr");
}
// do we actually have to adjust them?
if (ReferenceEquals(leftExpr.Type, rightExpr.Type))
{
return;
}
if (leftExpr.IsNumeric() && rightExpr.IsNumeric())
{
var leftSize = Marshal.SizeOf(leftExpr.Type);
var rightSize = Marshal.SizeOf(rightExpr.Type);
if (leftSize < rightSize)
{
leftExpr = ConstantHelper.TryEvalConst(root, leftExpr, ExpressionType.Convert, rightExpr.Type);
}
else if (leftSize > rightSize)
{
rightExpr = ConstantHelper.TryEvalConst(root, rightExpr, ExpressionType.Convert, leftExpr.Type);
}
else if (ReferenceEquals(leftExpr.Type, typeof(Single)))
{
// sizes are equal, so the other guy is probably Int32 or UInt32
rightExpr = ConstantHelper.TryEvalConst(root, rightExpr, ExpressionType.Convert, leftExpr.Type);
}
else if (ReferenceEquals(rightExpr.Type, typeof(Single)))
{
// sizes are equal, so the other guy is probably Int32 or UInt32
leftExpr = ConstantHelper.TryEvalConst(root, leftExpr, ExpressionType.Convert, rightExpr.Type);
}
else if (ReferenceEquals(leftExpr.Type, typeof(Double)))
{
// sizes are equal, so the other guy is probably Int64 or UInt64
rightExpr = ConstantHelper.TryEvalConst(root, rightExpr, ExpressionType.Convert, leftExpr.Type);
}
else if (ReferenceEquals(rightExpr.Type, typeof(Double)))
{
// sizes are equal, so the other guy is probably Int64 or UInt64
leftExpr = ConstantHelper.TryEvalConst(root, leftExpr, ExpressionType.Convert, rightExpr.Type);
}
}
else
{
throw new CompilationException(
String.Format(
"Argument types {0} and {1} cannot be auto-adjusted, try conversion",
leftExpr.Type.FullName, rightExpr.Type.FullName), root);
}
}