public override AST.Node ToAST(Env env)
{
/// Check the switch statement.
Switch sw = env.GetSwitch();
if (sw == null)
{
throw new Error(Pos, "default statement not in switch statement");
}
/// The expression of a case should be constant integer expression.
AST.ConstIntegerExpr c = expr.ToASTExpr(env) as AST.ConstIntegerExpr;
if (c == null)
{
throw new Error(Pos, "the expression of a case should be constant integer expression");
}
/// No two of the case constant expressions shall have the same value.
/// TODO: The conversion.
foreach (var e in sw.cases)
{
if (c.value == e.Item2.value)
{
throw new Error(Pos, string.Format("duplicate value {0} in case", c.value));
}
}
string label = env.AllocCaseLabel();
sw.cases.AddLast(new Tuple <string, ConstIntegerExpr>(label, c));
AST.Node s = stmt.ToAST(env);
return(new AST.Labeled(label, s));
}
public override AST.Node ToAST(Env env)
{
/// Check the switch statement.
Switch sw = env.GetSwitch();
if (sw == null)
{
throw new Error(Pos, "default statement not in switch statement");
}
/// At most one default statement in a switch.
if (sw.defaultLabel != null)
{
throw new Error(Pos, "at most one default label in a switch statement");
}
string label = env.AllocDefaultLabel();
sw.defaultLabel = label;
AST.Node s = stmt.ToAST(env);
return(new AST.Labeled(label, s));
}