New test failures - observer.exp, sigaltstack.exp, siginfo.exp

[Daniel Jacobowitz <drow at false dot org>]

These new tests are all failing on my i686-pc-linux-gnu system.

sigaltstack.exp fails like this:

finish
Run till exit from #0  catcher (signal=26) at /opt/src/gdb/src/gdb/testsuite/gdb.base/sigaltstack.c:71
Warning:
Cannot insert breakpoint 0.
Error accessing memory address 0xffffe420: Input/output error.
(gdb) FAIL: gdb.base/sigaltstack.exp: finish from catch LEAF

The problem is that the signal trampoline is read-only.  We can't set
software breakpoints there.  I suspect there is no way to do this portably.
Should we skip it instead, i.e. finish right to the place where the signal
was raised?

siginfo.exp fails like this:
(gdb) PASS: gdb.base/siginfo.exp: continue to stepi handler
bt
#0  handler (sig=26, info=0xbfffeda0, context=0xbfffee20) at /opt/src/gdb/src/gdb/testsuite/gdb.base/siginfo.c:31
#1  <signal handler called>
#2  main () at /opt/src/gdb/src/gdb/testsuite/gdb.base/siginfo.c:66
(gdb) PASS: gdb.base/siginfo.exp: backtrace for nexti
step
32      } /* handler */
1: x/i $pc  0x8048411 <handler+13>:     pop    %ebp
(gdb) step

Program exited normally.
(gdb) FAIL: gdb.base/siginfo.exp: step out of handler

I don't know if this is currently expected, or what.  It seems like a
bug.

observer.exp fails like this:

call observer_notify_normal_stop ()
too few arguments in function call
(gdb) PASS: gdb.gdb/observer.exp: sending notification (one observer)

Then all the counters are wrong, since the function call didn't happen. 
That's definitely a problem in the test script, since observer_notify_normal_stop
takes an argument; is this not a fatal condition on some other target?

-- 
Daniel Jacobowitz
MontaVista Software                         Debian GNU/Linux Developer