Compiling OS4 sources to target OS3

Hi
Is it possible to write OS4 programs who do not rely on specifcs features and build a 68k exécutable for AOS3?
So later I could target OS4 without modifying the code. (Not interested in ifdef stuff)

Thanks
Kamelito

Quote:

Yes.

Quote:

That could be a problem.

You'll need to define __USE_INLINE__ when you build for OS4.

You will also need to add code to GetInterface and DropInterface if you open any libraries (#ifdef __amigaos4__). You might be able to avoid that by using -lauto though.

There is few differences.

1. You don't need to open libraries on AmigaOS4.
2. If you OpenLibraries manually you need to also obtain a interface (main)
3. Close Libraries also need a close interface.

So this part of code might look a bit different.

4. Some OS3.x functions are obsoleted, mostly functions related to filesystem like opening files, and listing files and folders.

If you use -D__USE_INLINE__ on the compile line AmigaOS4 compiles AmigaOS3 pretty easy, if you don't you need to write IEXEC -> infront of all exec library functions and IDOS -> infront of all dos functions etc.

5. Some timer stuff has changed names.

@Kamelito
That is fairly easy to achieve using the PortablE language, since it already hides OS4's different library conventions. So as long as you avoid using OS4-specific stuff, you can simply recompile for OS3/AROS/MOS in most cases.

And for stuff which *is* OS4 specific, but which has equivalents on OS3/AROS/MOS (e.g. Picasso96 vs CyberGfx), I've written (but not documented!) quite a few simple abstractions (wrapper modules) to hide those differences. Those modules typically have names like 'CSH/pAmigaXXX' where XXX is the relevant Amiga library (although in the case of P96/CGX I use "RTG" instead).

Actually I was thinking about C but PortablE is an interesting option. I miss an OS X port though :)
Kamelito

Just add this at the beginning
#ifdef __amigaos4__
#define OS4
#else
#define OS3
#endif

#ifdef OS4
#define __USE_INLINE__
#define __USE_BASETYPE__
#define __USE_OLD_TIMEVAL__
#pragma pack(2)
#endif


and open the .library this way


/*==================================================================================*/
BOOL OpenAmigaLibraries()
{
/* Initialize the needed libraries */
#define LIBOPEN(libbase,name,version) libbase =(void*)OpenLibrary(#name,(ULONG)version); if(libbase==NULL) return(FALSE);
#define LIBOPEN4(interface,libbase) interface=(void*)GetInterface((struct Library *)libbase, "main", 1, NULL); if(interface==NULL) return(FALSE);



LIBOPEN(DOSBase,dos.library,36)
LIBOPEN(GfxBase,graphics.library,0)
LIBOPEN(IntuitionBase,intuition.library,0)
LIBOPEN(CyberGfxBase,cybergraphics.library,0)

if (OpenDevice(TIMERNAME, UNIT_MICROHZ, (struct IORequest *)&tr, 0L) != 0)
return(FALSE);
TimerBase = (struct Device *) tr.tr_node.io_Device;

#ifdef OS4
LIBOPEN4(IExec,SysBase)

LIBOPEN(NewlibBase,newlib.library, 52)
LIBOPEN4(INewlib,NewlibBase)

LIBOPEN4(IDOS,DOSBase)
LIBOPEN4(IGraphics,GfxBase)
LIBOPEN4(IIntuition,IntuitionBase)
LIBOPEN4(ICyberGfx,CyberGfxBase)

LIBOPEN4(ITimer,TimerBase);
#endif

return(TRUE);
}
/*======================================================================================*/
void CloseAmigaLibraries()
{
#define LIBCLOSE(libbase) if(libbase !=NULL) { CloseLibrary((struct Library *)libbase ); libbase=NULL; }
#define LIBCLOSE4(interface) if(interface!=NULL) { DropInterface((struct Interface*)interface ); interface=NULL; }


#ifdef OS4
LIBCLOSE4(INewlib)
LIBCLOSE(NewlibBase)

LIBCLOSE4(IDOS)
LIBCLOSE4(IGraphics)
LIBCLOSE4(IIntuition)
LIBCLOSE4(ICyberGfx)

LIBCLOSE4(ITimer)
#endif

LIBCLOSE(DOSBase)
LIBCLOSE(GfxBase)
LIBCLOSE(IntuitionBase)
LIBCLOSE(CyberGfxBase)

CloseDevice((struct IORequest *)&tr);
}
/*==================================================================================*/

Thanks but when you access libraries you'll still need all those interfaces naming right?
Kamelito

>you'll still need all those interfaces naming
No No you write the same code you did on OS3

It is the us __USE_INLINE__ that do the magic
It works this way in include/inline4/xxx.h:
#define OpenWindow(newWindow) IIntuition->OpenWindow((newWindow))

So you only need to write the os3 way:

OpenWindow(mynewwin);

Simple

Alain

PS: also remenber to declare the interface at the beginning of your code:

/*==================================================================*/
#ifdef OS4
struct Library* NewlibBase =NULL;
struct Interface* INewlib =NULL;

struct ExecIFace* IExec =NULL;
struct DOSIFace* IDOS =NULL;
struct GraphicsIFace* IGraphics =NULL;
struct IntuitionIFace* IIntuition =NULL;
struct CyberGfxIFace* ICyberGfx =NULL;

struct TimerIFace* ITimer =NULL;
#endif