Pragma and Object Files

Pragma and Object Files

[Andy Pekrins]

I have asked several people about this, but
haven't received the answer I need.  I am
using GNAT 3.10p, and know how to use a
pragma to import from another language.

The problem I am having is figuring out
how to actually (physically) link my
object file, from say, an assembler, to
my Ada program.

Do I need to convert my OBJ file to an
Ada library file?  If so, how could I
go about doing that?

For clarity, let me run this down real quick.
I have an assembler object (OBJ) file that I
need to import a few functions from into my
Ada program.  How do I like that object file
with my Ada program?  I know how to import the
functions using "pragma import..."

Also, if anyone has any clues about how to use
interrupts or output data to a port using Ada,
please let me know.

Thanks
storm@vci.net

Re: Pragma and Object Files

[Anonymous]

On Mon, 13 Apr 1998 14:10:39 -0500, Andy Pekrins <storm@vci.net> wrote:

> I have asked several people about this, but
> haven't received the answer I need.  I am
> using GNAT 3.10p, and know how to use a
> pragma to import from another language.
> 
> The problem I am having is figuring out
> how to actually (physically) link my
> object file, from say, an assembler, to
> my Ada program.
> 
> ...

Pass the object file to the linker:

gnatmake main_subprogram_name -largs asembler_routine.obj

Jeff Carter  PGP:1024/440FBE21
My real e-mail address: ( carter @ innocon . com )
"Go and boil your bottom."
Monty Python & the Holy Grail

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Re: Pragma and Object Files

[Andy Perkins]

Anonymous wrote:

> On Mon, 13 Apr 1998 14:10:39 -0500, Andy Pekrins <storm@vci.net> wrote:
>
> > The problem I am having is figuring out
> > how to actually (physically) link my
> > object file, from say, an assembler, to
> > my Ada program.
> >
> > ...
>
> Pass the object file to the linker:
>
> gnatmake main_subprogram_name -largs asembler_routine.obj

        I actually tried this before I posted that message.
        This causes an "unrecognized file format" error
        for the .obj file.  I believe the linker is looking for
        a GNAT .O object file...  Mine is an OBJ file
        coming from Borland's Turbo Assembler, and
        I have also tried MASM.

        storm@vci.net

Re: Pragma and Object Files

[Jacob Sparre Andersen]

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Andy Pekrins (storm@vci.net) asked about using assembler object (OBJ) files
with GNAT 3.10p.

Since you identify the object file as an "OBJ" file rather than an "o" file,
I suspect that the object file is in a M$ format.

GNAT uses a different format for object files, so you will have to see if the
GNU assembler can convert your file.

Good luck.

Jacob

PS: I have never tried this myself, so I might be completely off track.

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Re: Pragma and Object Files

[William Tanksley]

In article <6gvg24$m8u$1@news.uni-c.dk> sparre@meyer.fys.ku.dk (Jacob Sparre Andersen) writes:
>Andy Pekrins (storm@vci.net) asked about using assembler object (OBJ) files
>with GNAT 3.10p.

>Since you identify the object file as an "OBJ" file rather than an "o" file,
>I suspect that the object file is in a M$ format.

Agreed.

>GNAT uses a different format for object files, so you will have to see if the
>GNU assembler can convert your file.

The assembler won't help you at all -- object formats are not its job (and
it's not that good at its job anyways :).

There exists a program which converts from .obj to .o; I don't remember
anything useful about it, but you can almost certainly find some info at
DJ's web site at http://www.delorie.com/djgpp (this is the C compiler
whose backend is used as the backend for Gnat under DOS).  In the event
that nothing there helps, try asking the folk at news:comp.os.msdos.djgpp;
they've been quite helpful to me on occasion.

>Good luck.

Seconded.

>Jacob

>PS: I have never tried this myself, so I might be completely off track.

It's been quite a while... :)

>                        Have you played with your LEGO today?

-Billy

Re: Pragma and Object Files

[Geert Bosch]

Two ways:
  1. Pass the name of the object as linker argument to the gnatmake program.
     See the GNAT User's Manual for more details.

  2. Use the pragma Linker_Options ("yourobject.o") to link in your
     object file. See Ada Reference manual.

Reading the manuals, doing the Lovelace Tutorial and studying a few
examples is definately worth your time. See www.adahome.com for all 
these things.

Regards,
   Geert

Re: Pragma and Object Files

[Andy Perkins]

Geert Bosch wrote:

> Two ways:
>   1. Pass the name of the object as linker argument to the gnatmake program.
>      See the GNAT User's Manual for more details.
>
>   2. Use the pragma Linker_Options ("yourobject.o") to link in your
>      object file. See Ada Reference manual.

        The problem is that I don't have a .o file.  Mine is an obj file from
        Borland Turbo Assembler.  I can, of couse, tell there is a difference,
        but is there a way to convert an obj file to an o file?

        Thanks
        storm@vci.net

Re: Pragma and Object Files

[Albert K. Lee]

On Tue, 14 Apr 1998 13:11:00 -0500, Andy Perkins <storm@vci.net> wrote:
>Geert Bosch wrote:
>
>> Two ways:
>>   1. Pass the name of the object as linker argument to the gnatmake program.
>>      See the GNAT User's Manual for more details.
>>
>>   2. Use the pragma Linker_Options ("yourobject.o") to link in your
>>      object file. See Ada Reference manual.
>
>        The problem is that I don't have a .o file.  Mine is an obj file from
>        Borland Turbo Assembler.  I can, of couse, tell there is a difference,
>        but is there a way to convert an obj file to an o file?

An .obj file is an .o file, there is no difference ... DOS uses an
.obj file extension while many other OS's use .o instead.

-Albert

Re: Pragma and Object Files

[Stephen Leake]

Albert K. Lee wrote:
> 
> On Tue, 14 Apr 1998 13:11:00 -0500, Andy Perkins <storm@vci.net> wrote:
> >Geert Bosch wrote:
> >
> >> Two ways:
> >>   1. Pass the name of the object as linker argument to the gnatmake program.
> >>      See the GNAT User's Manual for more details.
> >>
> >>   2. Use the pragma Linker_Options ("yourobject.o") to link in your
> >>      object file. See Ada Reference manual.
> >
> >        The problem is that I don't have a .o file.  Mine is an obj file from
> >        Borland Turbo Assembler.  I can, of couse, tell there is a difference,
> >        but is there a way to convert an obj file to an o file?
> 
> An .obj file is an .o file, there is no difference ... DOS uses an
> .obj file extension while many other OS's use .o instead.

Sorry, but no. There are many different object file formats. Borland,
Microsoft, and GNAT are all different from each other. I don't know of
any way to directly convert one format to another, but there may be
something like that in the gnu bintools (but gnu bintools probably don't
know about Borland object format!).

You'll have to compile the assembler code with the gnu assembler. I
don't know if the assembler syntax is the same; the opcode mnemonics
probably are, but the macro language is probably different.

Good Luck!

-- 
- Stephe

Re: Pragma and Object Files

[Albert K. Lee]

On Thu, 16 Apr 1998 10:56:04 -0400, Stephen Leake <Stephen.Leake@gsfc.nasa.gov> wrote:
>Albert K. Lee wrote:
>> 
>> An .obj file is an .o file, there is no difference ... DOS uses an
>> .obj file extension while many other OS's use .o instead.
>
>Sorry, but no. There are many different object file formats. Borland,
>Microsoft, and GNAT are all different from each other. I don't know of
>any way to directly convert one format to another, but there may be
>something like that in the gnu bintools (but gnu bintools probably don't
>know about Borland object format!).
>
>You'll have to compile the assembler code with the gnu assembler. I
>don't know if the assembler syntax is the same; the opcode mnemonics
>probably are, but the macro language is probably different.
>
>Good Luck!

Sorry.  Where I come from (that is, the distant past), Intel specified
a common .obj format.  MASM code was easily linked with Turbo Pascal
and so on.  Is this not the case anymore?

Re: Pragma and Object Files

[William Tanksley]

In article <slrn6jcp90.agb.aklee@interport.net> aklee@spam.this.interport.net (Albert K. Lee) writes:

>Sorry.  Where I come from (that is, the distant past), Intel specified
>a common .obj format.  MASM code was easily linked with Turbo Pascal
>and so on.  Is this not the case anymore?

Your past isn't quite as distant as you might like to think.  Actually,
the a.out format used in Unix (generally using the .o prefix) was a lot
older than Intel.

The stuff produced by gcc anymore is usually in COFF format, which is now
being adopted by just about everyone (even MS uses a bastardized version
of COFF).

Thus, what you need is a obj2coff program, like I posted last time.  Are
my posts not propagating?  If not, you ought to be able to find one (fr
DOS) at http://www.delorie.com/djgpp.

-Billy