Re: extracting data access from functions

[Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>]

Em Tue, Jan 27, 2009 at 10:52:22AM -0500, Bart Trojanowski escreveu:
> * Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> [090127 10:27]:
> > With DWARF you can:
> > 
> > 1. find out struct layout
> > 2. find which functions have parameters of the type you want
> > 3. find which functions have variables of the type you want
> > 4. Know where such variables and parameters are on memory
> >    using DWARF location expressions (google for loc2c)
> > 
> > And that is it.
> 
> Thanks for the quick reply and clarification.
> 
> > Then... you would need to use libdisasm, that is part of elfutils but is
> > still a bit rough, being designed mostly for what you get from the
> > binutils utilities disassembly options.
> >
> > Combinining the above you will be able to do what you want.
> 
> That sounds interesting, but unfortunately the man pages notes that...
> >> The x86-64 architecture is not supported..LP
> ... being ia32-only makes it a no go for me.

Forget about the man page, this is very fluid, look at the latest
released version, 0.139, on fedorahosted, lemme dig the URL

https://fedorahosted.org/elfutils/

There is now a git tree, check it and, again, forget about the man page
:)
 
> Is there another route you could think of that is not platform-specific?
> 
> I guess binutils/objdump doesn't actually understand what's happening it
> just links it back to the code.  Hmm... and things like gdb are aware of
> things because they are platform specific.
> 
> > I want to look at usage patterns to figure out what are the member
> > working sets to pass that to my struct member reorganizing routines, run
> > with performance counters before/after, all automated, and reap the
> > profits 8)
> 
> I hear ya. :)
> 
> Thanks again.

Gimme 5 minutes and I'll get that done! ;-)

- Arnaldo
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