Re: remote dwarf info using libunwind

[Wu Zhou <woodzltc at cn dot ibm dot com>]

Alexandre Oliva wrote:
> On Sep  4, 2006, Wu Zhou <woodzltc@cn.ibm.com> wrote:
>
> > I am not sure too why we didn't use libunwind-ptrace.a directly
> > before.  One reason might be that it is not really a part of libunwind
> > API.  But my point is, as long as it is general enough, why can't we
> > make it part of libunwind API?
>
> What do you mean, not part of the libunwind API?  It's certainly not
> part of the run-time-for-local-process-unwinding API, but it
> definitely is part of the documented API of libunwind.

Below is a segment of comment from libunwind-ptrace.h:

/* Helper routines which make it easy to use libunwind via ptrace().
   They're available only if UNW_REMOTE_ONLY is _not_ defined and they
   aren't really part of the libunwind API.  They are implemented in a
   archive library called libunwind-ptrace.a.  */

It seems that libunwind developers are not sure how they expect these routines to be used.

> > > +lib::unwind::StackTraceCreator::unwind_destroy (unwargs *args)
>
> > This should be unwind_finish, I guess.
>
> Yes, sorry.  I failed to refresh the patch file after renaming the
> method.  I'm not sure whether I missed any other change, so here's the
> patch generated out of what I actually tested.

Good. I had a test with your patch.  TestStackBackTrace works ok with this patch.  Here are the output:

./TestRunner frysk.rt.tests.TestStackBacktrace
Running testBacktrace(frysk.rt.tests.TestStackBacktrace) ...Frame 1
        File: ../../frysk-clean/frysk-core/frysk/pkglibexecdir/funit-rt-looper.c
        Func: baz
        Line: 69
        Col: 0
        Addr: 134514264
Frame 2
        File: ../../frysk-clean/frysk-core/frysk/pkglibexecdir/funit-rt-looper.c
        Func: bar
        Line: 72
        Col: 0
        Addr: 134514286
Frame 3
        File: ../../frysk-clean/frysk-core/frysk/pkglibexecdir/funit-rt-looper.c
        Func: foo
        Line: 53
        Col: 0
        Addr: 134514315
Frame 4
        File: null
        Func: main
        Line: 0
        Col: 0
        Addr: 134514973
Frame 5
        File: null
        Func:
        Line: 0
        Col: 0
        Addr: 12773156
Frame 6
        File: null
        Func:
        Line: 0
        Col: 0
        Addr: 134514081
PASS

Time: 0.274

OK (1 test)

Regards
- Wu Zhou