Re: [Libunwind-devel] Function Address

[Jose Flavio]

Well, I tried to pick them from the elf file, but I couldnt, the main
problem is that there are several tables, each object has one, and there
are tables that are loaded when the dynamic loader loads a lib.
I couldnt figure out a way to access the whole memory in the elf.

The other doubt of mine is if that could raise problems in remote
debugging.

Futhermore, there is one old issue about powerpc and this function
address, because you could have functions that are not in the table,
although gdb do not do that, you could have a mixed problem, which some
some functions are called directly and others by the TOC. This is an old
problem in GDB. I think that the tdep_get_function_address should have
access to more information/structures so in future would be easy to make
a more complex function to resolve the function symbols.

What do you think about that?

On Tue, 2007-08-14 at 12:09 -0600, David Mosberger-Tang wrote:
> On 8/14/07, Jose Flavio <address@hidden> wrote:
> > Hi David,
> > I'm already working in adding the default get_function_address to other
> > archs. I was in doubt about putting a macro in elfxx other to put a
> > default function in dwarf. I think that the performance that you could
> > get with the macro would be minimal (if the compiler works well) and
> > would maintain the code better organized if a generic function would be
> > used, what do you think?
> 
> My main concern wasn't performance, but ease-of-maintenance.  I don't
> think it's a good idea to litter the other arches with code that's
> only used on PPC64.
> 
> > The second point of my concern is that I need to change the:
> > get_proc_name(..) in elfxx
> > to add a new parameter: unw_addr_space_t as
> > that I need to access the memory to read the table with function
> > descriptors.
> 
> Hmmh, can't you pick up the function descriptors from the ELF file?
> Then you shouldn't need the address_space argument.
> 
>   --david
-- 
Jose Flavio Aguilar Paulino
(address@hidden)

Toolchain Team
LTC, Linux Technology Center
IBM Brazil