[Info-vax] Error Messages in Basic - %BASIC-E-PARMODNOT, mode for parameter <n> of routine <procedure-name> not as declared

[Dave Froble]

On 6/8/2019 4:24 PM, Bob Gezelter wrote:
> On Saturday, June 8, 2019 at 2:21:45 PM UTC-4, Jeffrey H. Coffield wrote:
>> On 06/05/2019 07:45 AM, DuncanMorris wrote:
>>> On Wednesday, June 5, 2019 at 3:28:00 PM UTC+1, Jeffrey H. Coffield wrote:
>>>> The following compiles and runs for me on both Alpha and Itanium. You
>>>> must have something wrong in how you are declaring the function.
>>>>
>>>>            program test
>>>>
>>>>           external long function lib$convert_date_string
>>>>
>>>>           Declare Long            Date_Time_Context_gl
>>>>           Declare String          End_of_Month_Date_gs
>>>>           Declare Quad            End_of_Month_Date_Time_gq
>>>>           Declare Long            End_of_Month_Weekday_gl
>>>>           Declare Long            VMS_Condition_Code_gl
>>>>
>>>>           End_of_Month_Date_gs = '31-may-2019 01:23:45.67'
>>>>
>>>>           VMS_Condition_Code_gl   &
>>>>                   = LIB$CONVERT_DATE_STRING (End_of_Month_Date_gs, &
>>>>                   End_of_Month_Date_Time_gq, &
>>>>                   Date_Time_Context_gl )
>>>>
>>>>           print VMS_Condition_Code_gl
>>>>           print End_of_Month_Date_Time_gq
>>>>
>>>>           end
>>>>
>>>>
>>>>
>>>> On 06/05/2019 06:48 AM, Craig Dedo wrote:
>>>>> VMS_Condition_Code_gl   = LIB$CONVERT_DATE_STRING ( End_of_Month_Date_gs, End_of_Month_Date_Time_gq, Date_Time_Context_gl )
>>>
>>> Nothing wrong, per se, with the program.
>>>
>>> As Hoff has pointed out, the external definition in the library expects BASIC$QUADWORD for parameter 2. This is not seen as the same type as QUAD.
>>>
>>> Try this-
>>> program test
>>>
>>> %include "starlet"           %from %library   "sys$library:basic$starlet"      ! System Services declarations
>>> %include "$ssdef"              %from %library   "sys$library:basic$starlet"      ! condition codes
>>> %include "lib$routines"          %from %library   "sys$library:basic$starlet"      ! LIBRTL routines
>>>
>>>           Declare Long            Date_Time_Context_gl
>>>           Declare String          End_of_Month_Date_gs
>>>           Declare Quad            End_of_Month_Date_Time_gq
>>>           Declare Long            End_of_Month_Weekday_gl
>>>           Declare Long            VMS_Condition_Code_gl
>>>
>>>           End_of_Month_Date_gs = '31-may-2019 01:23:45.67'
>>>
>>>           VMS_Condition_Code_gl   &
>>>                   = LIB$CONVERT_DATE_STRING (End_of_Month_Date_gs, &
>>>                   End_of_Month_Date_Time_gq, &
>>>                   Date_Time_Context_gl )
>>>
>>>           print VMS_Condition_Code_gl
>>>           print End_of_Month_Date_Time_gq
>>>
>>>           end
>>>
>>> I1        12238     !     LIB$CONVERT_DATE_STRING
>>> I1        12239     !
>>> I1        12240     !     Convert Date String to Quadword
>>> I1        12241     !
>>> I1        12242     !     The Convert Date String to Quadword routine converts an absolute date
>>> I1        12243     !     string into a VMS internal format date-time quadword. That is, given
>>> I1        12244     !     an input date/time string of a specified format,
>>> I1        12245     !     LIB$CONVERT_DATE_STRING converts this string to a VMS internal format
>>> I1        12246     !     time.
>>> I1        12247     !
>>> I1        12248       EXTERNAL LONG FUNCTION  lib$convert_date_string &
>>> I1        12249                ( &
>>> I1        12250                    STRING  BY DESC, &
>>> I1        12251                    BASIC$QUADWORD  BY REF, &
>>> I1        12252                   OPTIONAL LONG  BY REF, &
>>>
>>
>> There are a number of places in both text libraries as well as .BAS
>> files that have the following "patch":
>>
>>         %IF %DECLARED(%BASIC$QUADWORD_DECLARED) = 0 %THEN
>>            RECORD BASIC$QUADWORD
>>               LONG FILL(2)
>>            END RECORD
>>            %LET %BASIC$QUADWORD_DECLARED = 1
>>         %END %IF
>>
>> because Basic didn't have a quad data type. It does now and this
>> could/should be cleaned up.
>>
>> There are other long time errors and omissions in Basic support that I
>> have had to keep my own fixed/stable versions of some of the library
>> files so my programs will work. Notably the files concerning XAB
>> structures for Basic would change/break with new versions of OpenVMS.
>>
>> If anyone is interested in fixing, I can dig up some small samples.
>>
>> Also, if there is a list of things to do, Basic still does not support a
>> get/find key "LT" or "LE" which RMS supports.
>
> Jeffrey,
>
> At first glance, when I encountered this I agreed. However, on detailed consideration, the problem is more complex.
>
> Changing the BASIC$QUADWORD definition to a simple quadword would invalidate all existing code. It would be a nasty incompatibility, causing a lot of rework to existing code.
>
> One could do something with conditional code, but it would be complex to implement and document.
>
> Hoff has referred to this type of problem using words along the line of "curse of compatibility". I am forced to agree. The solution (using a struct) made sense when done, but events have made the existing solution awkward and dated. Changing the solution breaks existing code.
>
> - Bob Gezelter, http://www.rlgsc.com
>

I guess where I'm confused is what is the difference between a RECORD 
structure that is basically 8 bytes, regardless of the makeup, and the 
BASIC QUAD variable definition.  I'm assuming there is a difference, 
since the reported problem exists.  But what is that difference, and, WHY?

If declaring a variable, and passing it by ref, then what I'd expect is 
simply the address of the 8 bytes.  What am I missing?

-- 
David Froble                       Tel: 724-529-0450
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