Re: GDB/MI design question re: Ada exception catchpoints

[Vladimir Prus <vladimir@codesourcery.com>]

On Wednesday, March 09, 2011 07:59:39 Joel Brobecker wrote:
> Hello all,
> 
> One of the guys at AdaCore would like to use CDT, and noticed that
> some normal CDT notifications do not get triggered when the program
> hits an Ada exception catchpoint.  We narrowed down the issue to
> the fact that we don't emit the stop reason:
> 
> (gdb)
> ~"\nCatchpoint 2, unhandled CONSTRAINT_ERROR at "
> *stopped,frame={addr="0x080497f2",func="test",args=[],file="/[...]/test.adb
> ",fullname="/[...]/test.adb",line="21"},thread-id="1",stopped-threads="all"
> ,core="1" (gdb)
> 
> In fact, looking deeper, we get the above, because, well, the
> "print_it" routine for Ada exception catchpoints does little more
> than `printf ("Catchpoint %d, %s at")', thus not handling the MI case
> at all.
> 
> But once I rewrote a bit the code to follow what other breakpoint
> "print_it" routines do, I now get the following output:
> 
> (gdb)
> *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",frame={addr="0x0000
> 000000402062",func="foo",args=[],file="foo.adb",fullname="/[...]/foo.adb",l
> ine="3"},thread-id="1",stopped-threads="all",core="3"
> 
> The front-end no longer has as much information as before.
> The fact that we've just hit an exception catchpoint can probably
> be deduced from the breakpoint number.  But we are missing the
> exception name.
> 
> I think that it would be sufficient to add an extra field providing
> that exception name:
> 
> *stopped,reason="breakpoint-hit",disp="keep",bkptno="1",exception-name="CON
> STRAINT_ERROR",frame={addr="0x0000000000402062",func="foo",args=[],file="fo
> o.adb",fullname="/[...]/foo.adb",line="3"},thread-id="1",stopped-threads="a
> ll",core="3"
> 
> If the field is missing, it means that we were unable to determine
> that exception name (in the CLI, we print "exception" instead of
> "CONSTRAINT_ERROR").
> 
> Would that be OK? 

That seems totally reasonable for me. I assume that for Ada catchpoints, "-break-list"
lists some special type?

- Volodya

-- 
Vladimir Prus
Mentor Graphics
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