I need FPC (or better, Pascal) console IO feature for my OS. That is, Write(Ln) (and possibly Read(Ln)) with variable number and type of arguments. I already have my own, but each can only take one argument. So, a statement like:

WriteLn('Hello, I am ',20,' years old');

must be splitted into:

WriteString('Hello, I am ');
WriteLong(20);
WriteStrLn(' years old');

This is very inconvenient. Moreover, assertions needs it. My first attempt, is to comment out {$undef FPC_HAS_FEATURE_CONSOLEIO} in my system.pas. But then, FPC argues about Unknown compilerproc "fpc_write_text_shortstr". I found it in text.inc, but it's only included if FPC_HAS_FEATURE_TEXTIO is defined. Knowing that I don't yet have any file system driver, I guess it's impossible to reach my goal by defining it.
What's the correct way?

Can you use variants?

procedure DebugLn(Args: array of const);
var
  i: Integer;
begin
  for i:=Low(Args) to High(Args) do begin
    case Args[i].VType of
    vtInteger: writeln(IntToStr(Args[i].vinteger));
    vtInt64: writeln(IntToStr(Args[i].VInt64^));
    ...
  end;
end;

See lazarus lclproc.pas for a complete example.

Mattias

Mattias Gaertner wrote

Can you use variants?

No, it requires objfpc support which I don't have yet (see my other post about FPC_HAS_FEATURE_HEAP). What if I declare fpc_write_text_shortstr with the same signature as the one in text.inc?

Can you undefine FPC_HAS_FEATURE_TEXTIO as well?

In the end, you have nothing left :-). Or is this the point?

What's the goal?

Micha

It's already undefined. Yes, I have nothing for now. In systemh.inc, you may find:

{$ifndef FPC_HAS_FEATURE_SUPPORT}
{$define FPC_HAS_FEATURE_HEAP}
{$define FPC_HAS_FEATURE_INITFINAL}
{$define FPC_HAS_FEATURE_RTTI}
{$define FPC_HAS_FEATURE_CLASSES}
{$define FPC_HAS_FEATURE_EXCEPTIONS}
{$define FPC_HAS_FEATURE_EXITCODE}
{$define FPC_HAS_FEATURE_ANSISTRINGS}
{$define FPC_HAS_FEATURE_WIDESTRINGS}
{$define FPC_HAS_FEATURE_TEXTIO}
{$define FPC_HAS_FEATURE_CONSOLEIO}
{$define FPC_HAS_FEATURE_FILEIO}
{$define FPC_HAS_FEATURE_RANDOM}
{$define FPC_HAS_FEATURE_VARIANTS}
{$define FPC_HAS_FEATURE_OBJECTS}
{$define FPC_HAS_FEATURE_DYNARRAYS}
{$define FPC_HAS_FEATURE_THREADING}
{$define FPC_HAS_FEATURE_COMMANDARGS}
{$define FPC_HAS_FEATURE_PROCESSES}
{$define FPC_HAS_FEATURE_STACKCHECK}
{$define FPC_HAS_FEATURE_DYNLIBS}
{$endif FPC_HAS_FEATURE_SUPPORT}

and my quick way to get rid of errors is to declare:

{$define FPC_HAS_FEATURE_SUPPORT}
{$undef FPC_HAS_FEATURE_HEAP}
{$undef FPC_HAS_FEATURE_INITFINAL}
{$undef FPC_HAS_FEATURE_RTTI}
{$undef FPC_HAS_FEATURE_CLASSES}
{$undef FPC_HAS_FEATURE_EXCEPTIONS}
{$undef FPC_HAS_FEATURE_EXITCODE}
{$undef FPC_HAS_FEATURE_ANSISTRINGS}
{$undef FPC_HAS_FEATURE_WIDESTRINGS}
{$undef FPC_HAS_FEATURE_TEXTIO}
{$undef FPC_HAS_FEATURE_CONSOLEIO}
{$undef FPC_HAS_FEATURE_FILEIO}
{$undef FPC_HAS_FEATURE_RANDOM}
{$undef FPC_HAS_FEATURE_VARIANTS}
{$undef FPC_HAS_FEATURE_OBJECTS}
{$undef FPC_HAS_FEATURE_DYNARRAYS}
{$undef FPC_HAS_FEATURE_THREADING}
{$undef FPC_HAS_FEATURE_COMMANDARGS}
{$undef FPC_HAS_FEATURE_PROCESSES}
{$undef FPC_HAS_FEATURE_STACKCHECK}
{$undef FPC_HAS_FEATURE_DYNLIBS}

in my system.pas. That way, I got my minimal working rtl (includes support for ShortStrings, Set, etc. so it's not totally *nothing*). I want to enable them one by one until all those defines are gone, so I have a full FPC support in my OS. And one of the first two (the other is HEAP) I can think of is the CONSOLEIO since I already have console printing ability. Perhaps someone have a dependency graph for all of these features?

Perhaps someone have a dependency graph for all of these features?

This is probably too hard to do. The goal of the feature approach is designed more towards the possibility to create a stripped rtl for existing targets. If you want only consoleio without file system support I fear you need to take your own approach

Florian Klaempfl wrote

If you want only consoleio without file system support I fear you need to take your own approach

No workaround?

I'll implement a file system soon, so I guess I'll be fine. Except there's another feature dependency for CONSOLEIO besides TEXTIO.

PS: FILEIO looks ... suspicious (i.e. not much different from TEXTIO).