Secondary Stack oddities w/ SGI Ada 95

[Viqar Abbasi <viqar@cae.ca>]

Hi all,

I have reduced my GNAT problem down to a very
basic "Hello World" program which crashes.  My
working environment is SGI Irix 6.5 w/ SGI Ada 95
1.2.  The application is a big flight simulator,
mostly containing C & Fortran.  We're phasing
Ada in, and its been mostly successful... However,
I've been tackling this crazy bug for a few weeks
now with no success... Here's how it works...

The following works fine:

procedure Report(Message : String) is
  Text_IO.Put_Line(Message);
end Report;

being called from...
procedure My_Test is
begin
  MOTS_IO.Report("Hello World!");
end My_Test;

The following crashes:

procedure Report(Message : String) is
  Text_IO.Put_Line("Hello " & Message);
end My_Test;

being called from...
procedure My_Test is 
begin
  MOTS_IO.Report("World!")
end My_Test;

The dbx dump is below.  My call is the only statement in the
package "Report_Test", in the procedure "My_Test".  To make things
slightly more complex, the package spec as the following...

Pragma Export(C, My_Test, "report_test__my_test_");

"My_Test" is being called from C, (as shown in the dbx output).

The key thing I'm seeing in the dbx output is this "Secondary
Stack" function "SS_Mark" generating a trap.

Any explanations?  

Thanks very much!

Puzzled Viqar.

> more dbx.out 
dbx version 7.2.1.1m (patch 3293) Jul 27 1998 15:23:33
Core from signal SIGQUIT: Quit
>  0 _kill(0x27b45, 0x3, 0x7ffee7c0, 0x0) ["kill.s":15, 0xfa4018c]
   1 abort_logger_(signal = 0x7fff2448, pc = 0x7fff24a0, link =
0x7fff2408, stack = (nil))
["/usr2/caelib/simex_plus/work/work6769/cel_routines.c":1233, 0x5bb870]
   2 DISPERR(sig = 11, code = 4, sc = 0x7fff2498)
["/mots2/cae/ship/istemp/cpulock/disp/disperr.c":44, 0x422598]
   3 SegVioHandler(sig = 11, code = 4, sc = 0x7fff2498)
["/usr2/cts/ctssrv_400/server.c":3523, 0x537bf8]
   4 _sigtramp(0xb, 0x3, 0x7fff2498, 0x0) ["sigtramp.s":71, 0xfae8034]
   5 system__secondary_stack__ss_mark() ["s-secsta.adb":205, 0x5f620530]
   6 mots_io__report(0x0, 0x60000, 0x10012190, 0x1001219c)
["/old/root/usr/people/viqar/mots/sacs/apr16/tmp/mots_io156395/mots_io.adb":0,
0x4d3e2c]
   7 report_test__my_test_(0x0, 0x60000, 0x10012190, 0x1001219c)
["/old/root/usr/people/viqar/mots/sacs/apr16/tmp/report_test147059/report_test.adb":0,
0x503da0]
   8 critsched()
["/mots2/cae/ship/istemp/cpulock/disp/rt_critsched.c":177, 0x41f688]
   9 CRITDSP() ["/mots2/cae/ship/istemp/cpulock/disp/rt_critdisp.c":207,
0x421f08]
   10 _sigtramp(0xe, 0x60000, 0x7fff2b88, 0x1001219c) ["sigtramp.s":71,
0xfae8034]
   11 __pause(0x0, 0x100394c0, 0x100394d0, 0x1) ["pause.s":20,
0xfac4808]
More (n if no)?   12 _pause(0x0, 0x100394c0, 0x100394d0, 0x1)
["pauseSCI.c":29, 0xfac487c]
   13 main(argc = 2, argv = 0x7fff2fa4)
["/mots2/cae/ship/istemp/cpulock/disp/rt_syncdisp.c":134, 0x41c714]
   14 __istart() ["crt1tinit.s":13, 0x41c430]