[fpc-devel] VMS Pascal Compiler mode

[Richard Apthorp]

Hi Sven,

Actually found that HP have a documented list:
http://h71000.www7.hp.com/doc/82final/6083/6083pro_032.html#extensions_app
I'm not sure I feel qualified to change the compiler but as I work on this porting project I will be creating a list of the main changes which I could then decide if beneficial to create a new compiler mode for (with a lot of help I hope!!!)
Thanks again for your advice, Richard.


-----Original Message-----
From: Sven Barth [mailto:pascaldragon at googlemail.com] 
Sent: 27 October 2014 11:38
To: FPC developers' list
Cc: Richard Apthorp
Subject: Re: [fpc-devel] VMS Pascal Compiler mode

On 27.10.2014 11:51, Richard Apthorp wrote:
> Hi Sven,
>
> Thanks for the reply. Yes some of it could be handled by a unit for 
> special types etc but not  sure what adding a new mode means or how to do it, could this handle differences such as - Type conversions:
> Var::integer  instead of integer(var)
> Passing in characters arrays:
> Procedure Proc(str : array [A..B] of char); Defaulting parameters 
> Procedure Proc(p1 : integer := 1; p2,p3:integer); And calling it in 
> different ways:
> Proc(,2,3);
> Proc(1,p3 := 3, p2:= 2);

Maybe you should indeed first try to list all differences then we could help you with judging how hard they are to be implemented. E.g. calling arguments by name is already implemented for some special cases (AFAIK for IDispatchable interfaces or something like that) so that would already be there. And then we could guide you for implementing them starting from the easy ones to the hard ones so that you could get familiar with the compiler.

Regards,
Sven

PS: Please keep the fpc-devel list as recipent as well (either as main To or as CC) so that others interested in this topic can read your messages as well. Maybe it would be better if you'd subscribe to the list, because then others don't need to CC you if they answer.

>
> -----Original Message-----
> From: Sven Barth [mailto:pascaldragon at googlemail.com]
> Sent: 25 October 2014 13:10
> To: FPC developers' list; Richard Apthorp
> Subject: Re: [fpc-devel] VMS Pascal Compiler mode
>
> On 24.10.2014 13:22, Richard Apthorp wrote:
>> Porting a large project running on the VMS operating system written 
>> in Pascal to Linux and Free Pascal.
>> However there is no compiler switch for HP VMS Pascal. Would be 
>> really useful if just the main syntax differences could be catered for eg:
>> Specifying parameter names in procedure calls (instead of overload) - 
>> I could provide a list.
>> Noticed GNU Pascal has such a compiler switch.
>> Anyway in the middle of writing a pre-processor to make the syntax 
>> changes but wondering if anybody has done something similar?
>> HP having just announced VMS retirement after 35 years there must be 
>> a lot of HP Pascal around some of which will need to be ported!
>
> I'm not aware of anyone developing a compiler mode for HP VMS Pascal (or Compaq Pascal as it seems to be called). So feel free to implement it yourself (you could start small by only adding the new mode first and maybe a compatibility unit for special type declarations that will be automatically loaded like the ObjPas unit for modes Delphi and ObjFPC or the MacPas unit for the Mac Pascal mode).
>
> Regards,
> Sven
>