[libunwind] libunwind-0.1 now available

[David Mosberger]

v0.2 of the unwind library is now available at:

  ftp://ftp.hpl.hp.com/pub/linux-ia64/libunwind-0.1.tar.gz

This should be thought of as an interim release, made available
primarily so it can be used in conjunction with GCC exception
handling.

The API changed in a fairly important way to make it easier to
implement exception handling: the machine state represented by the
unwind cursor now always corresponds to the instruction pointer value
that register IP contains.  In libunwind-0.0, the unwind cursor
contained the preserved register values as they existed on *entry* to
to the function that contains IP.

Like before, this release is far from being a complete or well-tested
implementation, so treat it as a works-in-progress.  Having said that,
the GCC exception handling that builds on top of libunwind-0.1 already
succeeds on more of the regression tests in the GCC distribution than
the default unwinder in GCC 3.1, so there is hope...

My plan is to next use libunwind for some debug-type applications (the
HP Ski simulator and gdb, hopefully) and once that works, I'll start
focusing on completing the implementation (e.g., finish unwind support
to cross signal handlers) and correctness testing.  Unwind support for
dynamically generated code is also a goal, but probably won't happen
until later.

On a final note, I'm experimenting with using bitkeeper as the source
code management tool for libunwind.  You can follow the project
at the following URL:

        http://unwind.bkbits.net/

To checkout the latest version of libunwind, you should be able to run
the command:

        $ bk clone bk://unwind.bkbits.net/stable
        $ cd stable
        $ bk -r get
        $ cd src
        $ make dep
        $ make

Enjoy,

        --david