Hi,

I've noticed this ages ago and found a work-around, but never reported it. I hit the same error again today and thought this time I would mention it.

In tiOPF we have some IFDEF's for the 'Windows' unit. Some units also use the 'SyncObjs' unit for critical section handling. If 'SyncObjs' unit appears before the 'Windows' unit, our code fails to compile with a error referring to the TCriticalSection class.

Does anybody know about this? Is there any permanent fix to that FPC doesn't depend on specific order in uses clause?

I'm now using FPC 2.2.0, but this issue has been around since 2.0.2.

------------[ copy ]------------------
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3491,13) Error: Unknown record field identifier "ENTER"

C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3491,18) Error: Illegal expression
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3497,15) Error: Unknown
record field identifier "LEAVE"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3497,20) Error: Illegal expression
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3503,13) Error: Unknown
record field identifier "ENTER"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3503,18) Error: Illegal expression
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3509,15) Error: Unknown
record field identifier "LEAVE"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3509,20) Error: Illegal expression
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3526,32) Error: Unknown
record field identifier "CREATE"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3532,13) Error: Unknown
record field identifier "FREE"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3532,17) Error: Illegal expression
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3544,13) Error: Unknown
record field identifier "ENTER"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3544,18) Error: Illegal expression
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3548,15) Error: Unknown
record field identifier "LEAVE"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3548,20) Error: Illegal expression
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3560,13) Error: Unknown
record field identifier "ENTER"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3560,18) Error: Illegal expression
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3564,15) Error: Unknown
record field identifier "LEAVE"
C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3564,20) Error: Illegal expression

C:\Programming\tiOPF2\Source\Core\tiUtils.pas(3569) Fatal: There were 19 errors compiling module, stopping

------------[ end ]-------------------

And here is an example of where the cursor lands to show the error...

function TtiMultiReadExclusiveWriteSynchronizer.LockForRead: boolean;
begin
  FCritSect.Enter;          // <<<<<<<<<  Cursor showing error
  try
    result:= CanLockForRead;
    if Result then
      Inc(FReadCount);
  finally
    FCritSect.Leave;
  end;
end;

Regards,
- Graeme -

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

Yes, use fully qualified names.

windows.tcriticalsection.
syncobjs.tcriticalsection.

For lower level stuff, you should use TRTLCriticalSection, never TCriticalSection.

It has the advantage of being portable.

I'm surprised you actually use the windows unit. That is Evil(tm).

Michael.

That should work....

The code in question is the tiOPF project which is shared with Delphi & FPC users. They (Delphi users) are all out of luck with the cross-platform abilities of FPC, so we have to use what both compilers support. For Delphi, that would be the 'Windows' unit.

Regards,
- Graeme -

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

Why doesn't Delphi compiler complain about it? A quick search revealed that Delphi's Windows.pas unit doesn't contain a TCriticalSection type definition, so why does FPC's Windows.pas unit? Why must FPC have two TCriticalSection type definitions?

Regards,
- Graeme -

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

It was translated automatically with the h2pas tool, probably with the -t option, which prepends a T to all types. For backwards compatibility we cannot revert this.

Michael.

Hmm, didn't older (<6) versions simply have this, and did synobjs get introduced later? In that case, if Delphi can break compat, so can we.

Marco van de Voort wrote

Hmm, didn't older (<6) versions simply have this, and did synobjs get introduced later? In that case, if Delphi can break compat, so can we.

I think I still have my copy of Delphi 5 lying around. If I can find it, I'll see if TCriticalSection is in that Windows unit and if SyncObjs unit existed in v5.

Regards,
- Graeme -

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

Hi, Graeme.

I've got D5 installed under Wine here, and the only thing found when grepping for tcriticalsection in the ./Source/Rtl/Win directory is the function "SetCriticalSectionSpinCount".

The SyncObjs unit does exist in D5.

~/.wine/drive_c/Program Files/Borland/Delphi5 $ find . -iname 'syncobj*' ./Lib/Debug/syncobjs.dcu
./Lib/syncobjs.dcu
./Source/Vcl/syncobjs.pas

Best regards,
Pete C.

D5 has Windows.TRTLCriticalSection, and SyncObjs.TCriticalSection which encapsulates a TRLTCriticalSection.

What about use uses Windows under ifndef fpc?

Joao Morais wrote

What about use uses Windows under ifndef fpc?

That will work for some units, but not all of them. Some units reference things in Windows unit not related to Critical Section, but I am definitely going to give this a try and see how far it takes me.

Thanks for the suggestion.

Regards,
- Graeme -

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

Maybe we could mark the declaration in unit Windows deprecated and later remove in 2.5.x (or whatever that becomes)?

Tomas

Tomas Hajny wrote

Maybe we could mark the declaration in unit Windows deprecated and later remove in 2.5.x (or whatever that becomes)?

I think this would be a good idea. It makes no sense having two TCriticalSection definitions. Plus it's much harder to maintain code shared between the Delphi and FPC compiler.

Regards,
- Graeme -

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

Yes and no, that would be the last resort solution yes, but I think here direct Delphi compat _and_ platform independance should weigh heavier than a misplaced backwards compability for which we have no indications.

So my final opinion would be: change it in 2.2.2 in 1st half 2008, not in 2.6 in first half 2011 or so.

That would be much preferred by me as well, but I don't carry any weight in pushing such FPC decisions.

Regards,
- Graeme -

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