So the way FreeInstance is called by adding it within a destructor isn’t exactly what I needed because it requires a destructor actually be present in the class.

The next thing I’d like to try is adding a procedure dynamically using nodes. I’ve seen how if statements are made doing things like:

                        addstatement(newstatement,cifnode.create(
                            caddnode.create(andn,
                                caddnode.create(unequaln,
                                    load_self_pointer_node,
                                    cnilnode.create),
                                caddnode.create(unequaln,
                                    ctypeconvnode.create(
                                        load_vmt_pointer_node,
                                        voidpointertype),
                                    cpointerconstnode.create(0,voidpointertype))),
                            ccallnode.create(nil,tprocsym(srsym),srsym.owner,load_self_node,[],nil),
                            nil));

but are there any examples of creating a procedural with nodes someone could point me to? I’d like to do something like:

procedure DoSomething(param);
begin
end;

so I could call the procedure with a parameter and have a block node (I think begin/end is a block node) so I could add some statements inside that. I’m having fun learning how the compiler works but it’s pretty complicated without any guidance.

Thanks.

Regards,
Ryan Joseph

Once again I think this is not useful so it can be disregarded.

I wanted to learn how I could call Free on class fields (like management operators call Finalize on records) but it’s more complicated than I thought (again). Records with management operators hook into the RTTI system it looks like, but how does a record with management operators get added to the classes RTTI information? I mean in TObject.CleanupInstance there is a vInitTable which gets set if the record has management operators in them but I can’t find where.

Regards,
Ryan Joseph

The whole VMT including vInitTable is generated by the compiler in ncgvmt. Take this example:

=== code begin ===

program thelloworld;
{$mode objfpc}
{$modeswitch advancedrecords}
type
   TTestRec = record
     f: LongInt;
     class operator Initialize(var aRec: TTestRec);
   end;
   TTest = class
     fRec: TTestRec;
   end;
class operator TTestRec.Initialize(var aRec: TTestRec);
begin
end;
var
   t: TTest;
begin
   t := TTest.Create;
end.

=== code end ===

If you compile this with -al you'll see the following symbols in the assembly code:

VMT_$P$THELLOWORLD_$$_TTEST: The VMT of the TTest class (look at rtl/inc/objpash.inc for the type TVmt to see how a VMT is structured) INIT_$P$THELLOWORLD_$$_TTEST: The init table of the TTest class (referenced from the VMT)
INIT_$P$THELLOWORLD_$$_TTESTREC: The init table of the TTestRec record (referenced from TTest's init table using an indirect reference)

Regards,
Sven