Exp TranslateDeclaration(FunctionDeclaration dec)
{
List <SymbolTable.Symbol> list = new List <SymbolTable.Symbol>();
for (FunctionDeclaration d = dec; d != null; d = d.Next)
{
if (Env.ValueEnvironment[d.Name] != null && Env.ValueEnvironment[d.Name] is StandardFunctionEntry)
{
Error.Report(d.Pos, "Function in standard libaray cannot be redefined");
}
else if (list.Contains(d.Name))
{
Error.Report(d.Pos, "Function cannot be redefined in a sequence");
}
else
{
list.Add(d.Name);
Types.Type result = d.Result == null ? Types.Type._void : TranslateType(d.Result).Actual;
Types.RECORD formals = TranslateTypeFields(d.Param);
Label label = new Label(d.Name + "_" + Count++.ToString());
Translate.Level level = new Translate.Level(Level, label, BoolList.BuildFromFieldList(d.Param));
Env.ValueEnvironment[d.Name] = new FunctionEntry(level, label, formals, result);
}
}
for (FunctionDeclaration d = dec; d != null; d = d.Next)
{
FunctionEntry function = Env.ValueEnvironment[d.Name] as FunctionEntry;
Env.ValueEnvironment.BeginScope();
Env.LoopEnvironment.BeginScope();
Translate.Level backup = Level;
Level = function.Level;
Translate.AccessList al = Level.Formals.Tail;
for (FieldList field = d.Param; field != null; field = field.Tail, al = al.Tail)
{
Types.Type type = Env.TypeEnvironment[field.Type] as Types.Type;
if (type == null)
{
Error.Report(field.Pos, "Undefined type '" + field.Name + "'");
}
else
{
Translate.Access access = new Translate.Access(Level, al.Head.Acc);
Env.ValueEnvironment[field.Name] = new VariableEntry(access, type.Actual);
}
}
ExpressionType et = TranslateExpression(d.Body);
Translate.ProcessEntryExit(Level, et.Exp, !(et.Type.CoerceTo(Types.Type._void)));
if (!et.Type.CoerceTo((Env.ValueEnvironment[d.Name] as FunctionEntry).Result))
{
Error.Report(d.Result != null ? d.Result.Pos : d.Body.Pos, "Type mismatched for function return value");
}
Env.ValueEnvironment.EndScope();
Env.LoopEnvironment.EndScope();
Level = backup;
}
return(Translate.TranslateNoOp());
}