[Llvm-bgq-discuss] 2 quick questions about upgrading

[Hal Finkel]

Hi John,

It is not exactly a glitch, but bgclang produces DWARF information that the older versions of gdb generally used on the BG/Q (both the totalview one and the stand-alone one) can't handle. You should at least grab the packages for the latest bgclang release, and those come with a newer gdb (in the bgclang-gdb package) that can handle the newer DWARF produced by bgclang.

There is also a flag to make Clang produce older DWARF information, but I don't know if that will fix things for you or not (there is -gdwarf-2 and -gdwarf-3 and -gdwarf-4 and -gstrict-dwarf).

 -Hal

----- Original Message -----
> From: "John A. Biddiscombe" <biddisco at cscs.ch>
> To: llvm-bgq-discuss at alcf.anl.gov
> Sent: Tuesday, February 3, 2015 1:41:03 AM
> Subject: [Llvm-bgq-discuss] 2 quick questions about upgrading
> 
> Hello list
> 
> 
> 
> I’m still using r209570-20140527 from early last year and have
> started more serious development on BGQ (rather than on IO nodes as
> previously).
> 
> 
> 
> I cannot debug my programs with totalview because the clang produces
> ‘incompatible’ binaries. (and I can’t use gdb either because gdb
> server gives me “invalid packet reply” errors which I haven’t
> managed to resolve).
> 
> Q1 : Are there any changes in newer bgq clang releases that solve
> this totalview binary problem (such as using newer libs or some
> other link changes)
> 
> 
> 
> I’ve got a problem where code runs in debug mode, but I have a
> segfault in release mode. Looks like some var is being optimized out
> when it should not.
> 
> Q2 : Are there any known bug or fixes that might encourage me to try
> a newer clang to get around this. (I haven’t ruled out a problem
> with my own code, but it’s looking like a compiler glitch to me at
> the moment)
> 
> 
> 
> Thanks
> 
> 
> 
> JB
> 
> 
> --
> 
> John Biddiscombe, email:biddisco @.at.@ cscs.ch
> 
> http://www.cscs.ch/
> 
> CSCS, Swiss National Supercomputing Centre | Tel: +41 (91) 610.82.07
> 
> Via Trevano 131, 6900 Lugano, Switzerland | Fax: +41 (91) 610.82.82
> 
> 
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> 

-- 
Hal Finkel
Assistant Computational Scientist
Leadership Computing Facility
Argonne National Laboratory