Re: Support Dwarf3 DW_CFA_val_* expressions

[Alexandre Oliva <aoliva@redhat.com>]

On Mar  4, 2006, Mark Kettenis <mark.kettenis@xs4all.nl> wrote:

> Thanks, the code looks fine.

Is this to be read as an ok to install?  (Sorry, I've been just a
lurker here in the past and I'm not entirely familiar with the rules
about who can approve what, so I thought I'd ask instead of ASSuming
:-)

> It's also good to have a few testcases,
> but I don't completely understand the testcases :(

You're not alone in that feeling, I assure you :-)

> You seem to mess
> with a lot of GCC internals in them.  Is the force_unwind() stuff
> really necessary?

Not for GDB, no.  We don't even reach that point.  I thought we'd be
better off keeping the testcase in sync with GCC, so all I did was to
add the initial comment.  The execution within GDB doesn't ever reach
the point of run-time-wise unwinding the stack.  GDB does something
similar by unwinding the stack to get a backtrace at the point from
which the GCC unwinder would be called.

> The tests are only enabled on Linux.  Is there a
> reason why they won't work on other i386 and amd64 systems that use a
> recent enough GCC?

I have no idea, I suppose someone with easy access to them could test
them and let me know :-)

At some point I had only the architectures listed in the .exp file,
but then I thought that some of them might not even use Dwarf2+ debug
info, and decided I'd go with only what I could test myself.

> And what would be the minimum version of GCC
> needed to run these tests?

To actually run them successfully to completion, without the debugger
interaction, you'd need some upcoming version of GCC, perhaps even
with patches yet to be checked in.  To compile it and run it up to the
point we need in the GDB test, I'm pretty sure even GCC 2.95 would do;
perhaps something even older than that.

-- 
Alexandre Oliva         http://www.lsd.ic.unicamp.br/~oliva/
Secretary for FSF Latin America        http://www.fsfla.org/
Red Hat Compiler Engineer   aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist  oliva@{lsd.ic.unicamp.br, gnu.org}