Re: Anyone built a debugger for Ada?

[haltarac@rain.org (Henri Altarac)]

: Also, there is an Ada_Connect package that allows us to talk to the
: 68000 over the bus. The team told me that when this package  is used,
: Adaprobe doesn't run. 
I don't know much about AdaConnect and its problems with AdaProbe.
However, I believe there must be a customizable part of the AdaProbe
kernel that runs on your target. In this part Alsys must have left
some routines like write-to-host and read-from-host for the low level
dialog between AdaProbe on the Host and its agent on the target. 
In those routines, there must be a way to redirect the AdaProbe protocol
through a serial line. It is tricky but can certainly be done.

Another solution. If your bus is a VME bus, you can probably add another
board in your rack like a MVME147 (a 68040, plenty of ram and an Ethernet
controller).Then your AdaProbe io routines can be
implemented by using AdaConnect to talk to an application on the MVME147
which will just be a relay between your target and the Host AdaProbe (going
through Ethernet).

All that is not easy but if you have a good base software team, they 
can make it happen (eventually since Alsys is late in fixing the
problems, you can ask them for some support/assistance).

: I'm aware of that. But how do you 'step' with a real debugger? Doesn't
: that also work with added code between every source line?

No. A debugger modifies a running program. When you set a break at a
given address, the debugger replaces the instruction at this address by
a special instruction (illegal instr, interrupt, trap or whatever) that
generates a software trap when executed (of course, the debugger must
declare itself as the trap handler). Another feature found on most
processors is a the Trace mode. When in this mode, the processor will
return control to the debugger after executing one instruction of
the user program. These two features combined let you implement
breakpoints and step into/over or anything else. On unix, you have
a general interface that hides all this. try man ptrace.
Anyway, this is not the way you want to go...

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Henri Altarac		haltarac@rain.org		Santa Barbara