Passing parameters of type 'ARRAY[0..MAXINDEX] OF ElementType' to C

[Rudolf Schubert]

        High Gaius,

        I'm facing a problem when trying to pass a parameter of typ String256
        to C, which I've defined like this:

        CONST
          len256=                       256;
        TYPE
          String256=                    ARRAY[0..len256-1] OF CHAR;

        In the appended example I've set up three DEFINITION MODULEs
        (unix1.def, unix2.def, unix3.def) each with a corresponding
        C file (unix1.c, unix2.c, unix3.c). There is only one simple
        function in these C files which should print out the length
        of the passed string and the string proper.

        unix1.def does NOT have 'FOR "C"' whereas unix2.def and unix3.def
        do have a 'FOR "C"' in the MODULE definition. In unix1.def and unix2.def
        the PROCEDURE ParamTest has got (my_str: String256) but in unix3.def
        I'm using 'varargs' (...).

        I'm seeing that only unix3 does give the expected results. unix1 and
        unix2 do either crash the programm or return wrong results.

        I do observe similar behaviour not only for

        type 'ARRAY[0..MAXINDEX] OF CHAR'

        but for instance also for

        type 'ARRAY[0..MAXINDEX] OF CARDINAL'

        Now my question is: how would I pass parameters of this type to
        C functions? I would suspect that this should not only work for
        'varargs' but also in the other cases? When using open ARRAYs in
        the PROCEDURE things are also working fine. It's just when using
        'non open' ARRAYs that the problem occurs.

BR

Rudolf

--
Rudolf Schubert                 \
Kirchstr. 18a                    \  mailto:rudolf@muc.de
82054 Sauerlach                   > http://www.dose.muc.de
Deutschland                      /   (alpine archkiste)
Tel. 08104/908311               /

wrk_gm2_16.tgz
Description: application/gzip