Hi,

I was reading a article on Delphi's WideString support. It mentions that under Delphi, WideStrings are not reference counted, but under Kylix they are.
http://tobias.feedian.com/2007/05/24/whats-wrong-with-delphis-widestring/

Using the following example program and compiling with 'fpc -al wstest.pas' under Linux to see the assembler file (not that I can remember anything of how assembler works). Looking at the asm code I see a call to FPC_WIDESTR_INCR_REF which I assume confirms that WideStrings under Linux using FPC is also reference counted.

Is the same true under Windows? Does that mean FPC doesn't have the WideString issues Delphi has?

-------------------------------------
program wstest;
uses
  Classes, SysUtils;
procedure Log(AParam: WideString);
var
  lparam: WideString;
begin
  lParam := AParam;
end;
begin
  Log('This is a test');
end.
----------------------

<....snip....>
# [12] lParam := AParam;
leal -4(%ebp),%eax
call FPC_WIDESTR_INCR_REF
leal -8(%ebp),%eax
call FPC_WIDESTR_DECR_REF
movl -4(%ebp),%eax
movl %eax,-8(%ebp)
<...snip...>

Regards,
- Graeme -

_______________________________________________
fpGUI - a cross-platform Free Pascal GUI toolkit
http://opensoft.homeip.net/fpgui/

Widestrings under windows are not reference counted for OLE compatibility, on all other platforms they are reference counted.

peter green wrote

> Widestrings under windows are not reference counted for OLE compatibility, on all other platforms they are reference counted.

Thanks!

Regards,
- Graeme -

_______________________________________________
fpGUI - a cross-platform Free Pascal GUI toolkit
http://opensoft.homeip.net/fpgui/

Widestrings were reference counted on all platforms before FPC 2.2 . With version 2.2 FPC switched to the Delphi behaviour on Windows in order to achieve COM compatibility.
Cossplatform unicode applications like MSEide+MSEgui: http://sourceforge.net/projects/mseide-msegui
suffer from the performance loss due to the non reference counted widestrings on Windows. MSEide+MSEgui is completely done with widestrings. I suggest to introduce a new COM compatible OLE-string type and let widestrings be reference counted on all platforms. It seems that CodeGear plans to go a similar route: http://groups.google.ch/group/borland.public.delphi.non-technical/msg/7caeced42f1934a4?hl=en& The introduced string handling for the "Unicode VCL" is equivalent to the string handling in MSEgui BTW.

Martin

[...] http://groups.google.ch/group/borland.public.delphi.non-technical/msg/7caeced42f1934a4?hl=en&

The text mentions 'IntPtr' for FPC's 'PtrInt'.
Oh boy, they really want to be FPC incompatible. ;)

Mattias