Re: coffread.c extension for DLLs without debugging symbols

["Raoul Gough" <RaoulGough@yahoo.co.uk>]

"Elena Zannoni" <ezannoni@redhat.com> wrote in message
news:15898.13355.611979.991969@localhost.redhat.com...
> Raoul Gough writes:

>  > OK, this is no problem. In fact the K&R style functions are
straight
>  > out of pe-dll.c from ld, and I think there are existing bfd_
functions
>  > that do the same thing. I'll fix the code to use the bfd
functions
>  > (removing the K&R style functions) and also sort out the other
>  > formatting issues as well.
>  >
> thanks

Actually, I've left those functions in after all, but reformatted
them. Turns out that the bfd_ functions are different enough that I
didn't want to try the change (if it's not broken....).

[snip]
>  > > As far as the new code being triggered, could you do it based
on the
>  > > existance of some particular section/data in the objfile?  I
see
>  > that
>  > > you bail out of read_pe_exported_syms if there are no exports,
could
>  > > something on the same flavour be done? (like using
bfd_get_flavour,
>  > > or bfd_get_section_by_name, etc)
>  >
>  > Not sure what you mean here - it currently uses both the pe_file
flag
>  > and bfd_get_target() to check whether to proceed with the
processing.
>  > I could also add a get_section_by_name(".edata") I guess.
>  >
>
> Usually gdb triggers reading one debug format or another depending
on
> the presence of certain sections names. So here, instead of looking
at
> the target you can look at the existance of .edata.
>
> Look at elfread.c and how it finds which debug format is used.  It
is
> not using get_section_by_name(), but the idea is similar.

I've decided to stick with the bfd_get_target, because I'd like to
make sure that the code only attempts to process i386 PE files (it
might work on, say, Alpha, but I can't test it). I'm sure there are
other ways to check this, but coffread.c already uses the target name
to set up the pe_file flag.

Note also that the .edata section can be empty (seems to happen with
.exe files).

>
>  > >
>  > > About location of the code, add maybe a coff-pe-read.c? (ulgh)
But
>  > > since it deals with reading symbols, I would think it more
logical
>  > to
>  > > stay in some object/debug format related file rather than in a
>  > target
>  > > related file.
>  >
>  > I agree - there will still have to be a hook in coffread to call
the
>  > new function, though. Does this also mean changing the config
somehow
>  > to make it compile the new module under the right circumstances?
Any
>  > advice on doing this?
>  >
>
> No, I just meant that the functions to manipulate these symbols
could
> be moved into their own file. Gdb always includes all the
> debug/objfile readers in each build, so no need to tweak configure.

coff-pe-read it is (see my other posting for the new patches).

Regards,
Raoul Gough.