/// <summary>
/// Creates a catch block.
/// </summary>
/// <param name="variables">The variables introduced by the catch block.</param>
/// <param name="type">The type of the exceptions to handle.</param>
/// <param name="variable">The variable to assign a caught exception to.</param>
/// <param name="body">The body of the catch block.</param>
/// <param name="filter">The filter to apply.</param>
/// <returns>The created <see cref="CSharpCatchBlock"/>.</returns>
public static CSharpCatchBlock MakeCatchBlock(IEnumerable <ParameterExpression> variables, Type type, ParameterExpression variable, Expression body, Expression filter)
{
var variablesList = CheckUniqueVariables(variables, nameof(variables));
Requires(variable == null || AreEquivalent(variable.Type, type), nameof(variable));
if (variable != null)
{
if (variable.IsByRef)
{
throw LinqError.VariableMustNotBeByRef(variable, variable.Type);
}
// REVIEW: See UsingCSharpStatement for a similar situation.
if (!variablesList.Contains(variable))
{
throw Error.CatchVariableNotInScope(variable);
}
if (type == null)
{
type = variable.Type;
}
else if (!AreEquivalent(type, variable.Type))
{
throw Error.CatchTypeNotEquivalentWithVariableType(type, variable.Type);
}
}
else if (type != null)
{
ValidateType(type);
}
else
{
type = typeof(object); // NB: Used to catch all.
}
RequiresCanRead(body, nameof(body));
if (filter != null)
{
RequiresCanRead(filter, nameof(filter));
if (filter.Type != typeof(bool))
{
throw LinqError.ArgumentMustBeBoolean();
}
}
return(new CSharpCatchBlock(variablesList, type, variable, body, filter));
}
