[fpc-devel] Using Macros for IInterface

[Graeme Geldenhuys]

On 2012-09-25 22:16, Henry Vermaak wrote:> I've used a macro for this in 
the past.  E.g. :
 >
 > {$macro on}
 > {$ifdef windows}
 >    {$define CCONV:=stdcall}
 > {$else}
 >    {$define CCONV:=cdecl}
 > {$endif}
 >
 > Then use CCONV where you would specify the calling convention.


Couldn't something like this be applied to IInterface too?  So we can 
get rid of those horrible IFDEF lines. If you don't know what I am 
talking about, have a look at the IInterface definition.


        IUnknown = interface
          ['{00000000-0000-0000-C000-000000000046}']
          function QueryInterface({$IFDEF 
FPC_HAS_CONSTREF}constref{$ELSE}const{$ENDIF} iid : tguid;out obj) : 
longint;{$IFNDEF WINDOWS}cdecl{$ELSE}stdcall{$ENDIF};
          function _AddRef : longint;{$IFNDEF 
WINDOWS}cdecl{$ELSE}stdcall{$ENDIF};
          function _Release : longint;{$IFNDEF 
WINDOWS}cdecl{$ELSE}stdcall{$ENDIF};
        end;
        IInterface = IUnknown;


And all those IFDEF's must go in your own code too when you implement a 
class with IInterface support.  Yuck!!

Cheers,
   - Graeme -