BlackBox Component Builder

Chris has found better solution of this problem without additional procedures.

b8281d75

The bug fix merged with master in 46f8e3e3

Marco Ciot:

The affected module is DevCPT.

The bug is very old. I guess it was there in the original Oberon Compiler written by N. Wirth, already. (And never discovered so far?!?) If this particular language construct is used, however, it leads to Heap Corruption.

Marco Ciot:

Fixed excerpt from DevCPT:

    PROCEDURE OutRecurseBaseTypeForHdFlds (typ: Struct; adr: INTEGER);
    BEGIN
        IF typ.BaseTyp # NIL THEN OutRecurseBaseTypeForHdFlds(typ.BaseTyp, adr); END;
        OutFlds(typ.link, adr, FALSE);
    END OutRecurseBaseTypeForHdFlds;

    PROCEDURE OutHdFld(typ: Struct; fld: Object; adr: INTEGER);
        VAR i, j, n: INTEGER; btyp: Struct; debugNow: BOOLEAN;
    BEGIN
        IF typ.comp = Record THEN
            IF typ.BaseTyp # NIL THEN OutRecurseBaseTypeForHdFlds(typ.BaseTyp, adr); END;
            OutFlds(typ.link, adr, FALSE);

Additionally the finger printing needs to be fixed, as well:

    PROCEDURE FPrintStr*(typ: Struct);
        VAR f, c: SHORTINT; btyp: Struct; strobj, bstrobj: Object; pbfp, pvfp: INTEGER;

        PROCEDURE ^FPrintFlds(fld: Object; adr: INTEGER; visible: BOOLEAN);

        PROCEDURE FPrintRecurseBaseTypeForHdFlds (typ: Struct; adr: INTEGER);
        BEGIN
            IF typ.BaseTyp # NIL THEN FPrintRecurseBaseTypeForHdFlds(typ.BaseTyp, adr); END;
            FPrintFlds(typ.link, adr, FALSE);
        END FPrintRecurseBaseTypeForHdFlds;

        PROCEDURE FPrintHdFld(typ: Struct; fld: Object; adr: INTEGER);    (* modifies pvfp only *)
            VAR i, j, n: INTEGER; btyp: Struct;
        BEGIN
            IF typ.comp = Record THEN
                IF typ.BaseTyp # NIL THEN FPrintRecurseBaseTypeForHdFlds(typ.BaseTyp, adr); END;
                FPrintFlds(typ.link, adr, FALSE);

Josef Templ wrote:

The names OutRecurseBaseTypeForHdFlds and FPrintRecurseBaseTypeForHdFlds
are instructive for reviewing purposes.

The names of the new procedures are inappropriate.
Use OutHdBaseFlds and FPrintHdBaseFlds.
It is hard to imagine that any other name would be more 'natural'
and the currently used names are certainly not fitting with the existing names.