pragma import problem ( also OS/2 : gnat 4emx )

pragma import problem ( also OS/2 : gnat 4emx )

[Ralph Paul]

Hello,

I am currently working on a GNAT-2.00  for emx.
Last night I encountered an interesting problem :

The linker ld was not able to link with the os2.a lib
because it couldn't find the required C - functions !
Therefore I was unable to do tasking as well as use the
pm-bindings.

After comparing different runtime files which import c-functions
I stumbled across the solution. It is rather simple :


All I had to do was to erase " Link_Name => " and recompile
the changed runtime files ( and it's dependants ).

I think on Linux there is a similar problem ?!

Now i am able to use the pm-bindings and to compile tasking 
programs. There is however still one problem left. It seems 
that the c-library is not completely multi-threaded safe but
E. Mattes mentions a way around this problem the doc files.

( strange thing : If I step thru the tasking test prog. with emx-gdb 
it works fine !. Without emx-gdb it raises an unhandled 
execption after running for a few iterations . )

I will work on this . I hope to be able to get this done
during the next days. If it works out i will announce it
to gnat-report and comp.lang.ada. 
BTW i sent NYU-GNAT a message on this OS/2 stuff and didn't get
any response yet ( Hello GNAT (;-)  ). 

Many thanks in advance,

Ralph Paul

---------------------------------------------------
E-Mail :

	 ralph@ifr.luftfahrt.uni-stuttgart.de
or	 ralph.paul@studbox.uni-stuttgart.de 


---------------------------------------------------


   

Re: pragma import problem ( also OS/2 : gnat 4emx )

[Robert Dewar]

Regarding the use of link name (incidentally I did send a direct message
already, so if it didn't arrive, must be an email addressing problem).

Generally NEVER use link name, use external name instead, and use for the
external name the name as it appears in the external language. This
is much more portable. If you use link name, then you have to know
system dependent things like whether an underscore is prefixed.

Note: there has been some glitch in the OS/2 version in this area in the
past, but you should still use external name. Anyway, this will clean up
in the EMX vesion we are hopeing to distribute soon.

Re: pragma import problem ( also OS/2 : gnat 4emx )

[Vladimir Vukicevic]

In article <3flfot$1ac9@info4.rus.uni-stuttgart.de>
ralph@ifr.luftfahrt.uni-stuttgart.de (Ralph Paul) writes:
> After comparing different runtime files which import c-functions I
> stumbled across the solution. It is rather simple :
>
> All I had to do was to erase " Link_Name => " and recompile the
> changed runtime files ( and it's dependants ).
>
>  I think on Linux there is a similar problem ?!

Umm, unless I, and grep, are mistaken, the GNAT runtime code -never- uses
Link_Name; Linux has no problems with the runtime. The only problem that's
left with gnat for linux is the lack of a pthreads library (which I might
port when I have some free time).

	- Vladimir
	- vladimir@intrepid.com