Ada + Assembly ...

Ada + Assembly ...

[Albert K. Lee]

I am trying to create a program with Ada and Assembly components on a
Pentium Linux (2.0.30) system with GNAT 3.09.  I have achieved
successful linking, but the program segfaults at the point where the
Ada program calls the assembly language routine.

I've had previous experience with assembly only under DOS on a '286;
Linux on a 32-bit processor is quite a different environment.  I am
using pragma Import with the C calling convention.  For now, the
assembly routine (declared as a procedure) just does a 'ret'.

I compile first the Ada file to an object file using "gnatmake
<blah>.o", then I run the assembly file through gcc, then run
"gnatbind -x" on the .ali file, and finally run gnatlink on the .ali
file plus the assembly object file.

Since I am winging this mini-project (the only documentation I found
was in the RM), I'd rather see snippets of working code than have
others attempt to correct my error-filled trials.

One last note ... I made one or two simple programs using just
assembly (they simply do some register addition and exit, *without*
segfaulting, heh), but I cannot debug them (and check what they're
actually doing) under gdb 4.16 with GNAT extensions -- gdb reports "no
debugging symbols found" and "can't find a default source file".  Yes,
I used the -g flag during compilation and linkage.

I'd really appreciate any pointers, hints, tips, or techniques.  TIA

-Albert

Re: Ada + Assembly ...

[Robert Dewar]

Albert asked


<<One last note ... I made one or two simple programs using just
assembly (they simply do some register addition and exit, *without*
segfaulting, heh), but I cannot debug them (and check what they're
actually doing) under gdb 4.16 with GNAT extensions -- gdb reports "no
debugging symbols found" and "can't find a default source file".  Yes,
I used the -g flag during compilation and linkage.
>>


If you write in assembly, it is your responsibility to generate the
necessary debugging directives, the assembler will not do it for you!