Procedural Variables from delphi

[PaulAtreides62]

My code is part of a windows 32bit library, realized , compiled end built under delphi ( 4, 5, ecc..) without errors.

I want to port it under lazarus ( 0.9.26 ) for windows 32bit.

Here my code, where i suppressed the other not important lines:

Code: [Select]

library Libreria;

{$mode objfpc}{$H+}

uses
 Windows,
 Messages,
 SysUtils,
 Classes,

(*
Graphics,
Controls,
Forms,
StdCtrls,
*)
Dialogs;
...

TYPE   TAzione = PROCEDURE( Action : PChar );
...

VAR    var_azione : TAzione; 
...

PROCEDURE Pippo( Puntatore : POINTER );
BEGIN
 var_azione := @TAzione( Puntatore );                <<<<<   ERROR
END;
...

EXPORTS Pippo;
...


The compilation error , into Pippo PROCEDURE, is

Code: [Select]

Libreria.lpr(175,23) Error: Incompatible types: got "Pointer" expected "<procedure variable type of procedure(PChar);Register>"

can you help me? 

[theo]

Have you tried many things before posting? ;-)

This should work:

PROCEDURE Pippo( Puntatore : POINTER );
BEGIN
 var_azione := TAzione( Puntatore );
END; 

or put {$mode delphi} instead of {$mode objfpc} in the source.

[PaulAtreides62]

I have tried both solutions, so that compiling and building is ok, but when when i use it calling a funtion ( it's a plug-in of other software ) , i obtain an access violation error:

Code: [Select]

Access violation at adress xxxx.. in module Libreria.dll . Read of address 0000000

thank you at all

[Phil]

It looks like you're putting a form in a library (DLL). That's a know problem with the win32 version of Lazarus. I've been successful at putting very large form-based apps in a library on OS X, but they crash on Windows with Lazarus and work fine with Delphi.

Can you continue using Delphi on Windows and use Lazarus for other platforms until this is fixed?

Look in the bug tracker for discussion of this issue.

Thanks.

-Phil

[PaulAtreides62]

It looks like you're putting a form in a library (DLL). That's a know problem with the win32 version of Lazarus.

It is so, Phil.

Can you continue using Delphi on Windows and use Lazarus for other platforms until this is fixed?

Yes, but when you foresee that it will happen?
thanks 

[Phil]

There's a bounty now for fixing this bug (7182):

http://wiki.lazarus.freepascal.org/Bounties#Windows_bounties

Maybe you could add some $ to Oleg's bounty and thus increase the attractiveness of this to a potential fixer.

Thanks.

-Phil