[ltt-dev] gdb-7.2 can't build with lttng-ust-0.12

[Cui, Dexuan]

Mathieu Desnoyers wrote:
> * Cui, Dexuan (dexuan.cui AT intel.com) wrote:
>> Due to the API changes in lttng-ust 0.12,  gdb's latest version 7.2
>> can't build with lttng-ust:
>> http://sourceware.org/ml/gdb/2011-04/msg00140.html 
>> 
>> Hope somebody here can help gdb to work with ust 0.12. :-)
> 
> Hi Dexuan,
> 
> We're currently doing instrumentation API changes in UST. At the
> moment, it is in the git tree, planned for release in UST 0.13. Our
> goal is to perform this painful (but required) step sooner than later
> so that we minimize the amount of pain for our user-base.
Hi Mathieu,
Thanks very much for the info!
I'm looking forward to seeing 0.13 released and
hope it can build with gdb-7.2. :-)

> Also, we should reopen the discussion on the way the UST Markers
> collect the registers for GDB, because the current way involves a
> _lot_ of ugly assembly code. It should be possible to only use a
> volatile inline asm to specify input constraints on the target marker
> parameters, and keep the instruction pointer address that corresponds
> to this inline asm in a section known by gdb (so gdb could use the
> drawf info to fetch data from registers/memory). If you can ensure
> that this would fit gdb's requirements, I could clean up the marker
> code and we could resync the APIs together. We could also provide
> this for UST Tracepoints in the same go, with pretty much the same
> interface as we'd use for UST Markers. I am aware that this would
> require change on the GDB side, but I think it's better to
> synchronise our effort rather than to shoot at different targets.
Unluckily I'm pretty new to gdb and know few about this now.
Let me Cc the gdb mailing list for more thoughts(hope this cross-posting
wouldn't bother people).

Thanks!
 -- Dexuan