Hi all,

I have an object stream for a component with a published property Color: TColor. The stream contains the statement: Color = clRed
Since 'clRed' is an identifier, TReader lookups for an IdentToInt function via FindIdentToInt declared in classes.pp. FindIdentToInt needs a pointer to a TTypeInfo.

The problem is that the TypeInfo pointer differs from unit to unit. A TypeInfo(longint) in classes.pp is not the same as a TypeInfo(longint) in the program. This is incompatible to Delphi.
So, the program can't register a valid TypeInfo pointer.

I guess, it's not easy to fix this, so I suggest a workaround:

The function FindIdentToInt can be extended to not only check for TypeInfo pointers, but also for the values in the typeinfo:

function FindIdentToInt(AIntegerType: Pointer): TIdentToInt;
var
  i: Integer;
begin
  with IntConstList.LockList do
  try
    for i := 0 to Count - 1 do
      with TIntConst(Items[I]) do begin
        if (IntegerType = AIntegerType)
        // start of workaround --------------------
        or ((PTypeInfo(AIntegerType)^.Name = PTypeInfo(IntegerType)^.Name)
          and (PTypeInfo(AIntegerType)^.Kind = PTypeInfo(IntegerType)^.Kind))
        // end of workaround --------------------
        then
          exit(IdentToIntFn);
      end;
    Result := nil;
  finally
    IntConstList.UnlockList;
  end;
end;

The same can be applied to the FindIntToIdent function.

Mattias Gaertner

Will this not lead to problems with enumerated values ?

You can perfectly have the same enumerated name in 2 units for 2 different enumeration types.

Unita.EnumA = (enOne,onTwo,EnThree);
Unitb.EnumB = (enZero,enOne,enTWo);

This will lead to incorrect results as 'enOne' will have ordinal values 0 and 1 depending on which unit you take...

So I think a compiler solution is in order, here. Florian, any ideas how this should be solved ? Maybe typeinfo should always be included in the unit where something is defined ?

OTOH, longint is a special case, it is an internal compiler type...

Michael.

Here the property types can be EnumA and EnumB, so I think this should work. But of course you're right, the name and kind is not sufficient to distinguish types. OTOH FindIdentToInt is currently rather useless. So, I guess no one uses it. With the workaround it works pretty well in the intended way.

So I think a compiler solution is in order, here. Florian, any ideas how this should be solved ? Maybe typeinfo should always be included in the unit where something is defined ?

Sounds good.

OTOH, longint is a special case, it is an internal compiler type...

Ok, maybe typeinfo(longint) was a bad example. I don't want to register longint.

Mattias

Why else do you need it if not for integer types ? It's not needed for enumeration types, since there you can use getenumname. In all other cases, the implementation should work as it is, no ?

Michael.

I ment, I don't want to register names for 'longint'. I want to register names for integer types like
type TColor = -$7FFFFFFF-1..$7FFFFFFF;

This is not an internal compiler type and has a typeinfo of its own. But with the current implementation I can't register anything for it.

In all other cases, the implementation should work as it is, no ?

I hope the typeinfo function will improve eventually. For now the workaround can do the job.

Mattias