This is the mail archive of the
systemtap@sourceware.org
mailing list for the systemtap project.
Re: [BUG?] semantic error: failed to retrieve location attribute for local
On Wed, Dec 06, Frank Ch. Eigler wrote:
> Once the marker-based static instrumentation widget makes it into the
> official kernels, then sprinkling them into the more valuable inline
> functions will let us hook up systemtap probes with no reliance on
> debugging information.
Ouch! My experience is that this doesn't really work for debugging purpose.
I bet the right marker is always missing when you need it most :(
> > <1><6dd453>: Abbrev Number: 63 (DW_TAG_subprogram)
> > DW_AT_name : (indirect string, offset: 0x38365): real_lookup [...]
> > DW_AT_inline : 1 (inlined) [...]
> > <2><6dd471>: Abbrev Number: 61 (DW_TAG_formal_parameter)
> > DW_AT_name : (indirect string, offset: 0x43b44): name
> > DW_AT_decl_file : 1
> > DW_AT_decl_line : 446
> > DW_AT_type : <6d7bc9>
> > <2>[...]
>
> Note that there is no DW_AT_location data, which we could use to
> locate the values in memory/registers at run time.
Hmm, yes. The DW_AT_location only exists for one of the paramters. Guess I'll
have to bug the gcc folks next door :)
Anyway, thanks a lot!