Change an object file without explicit copying

Change an object file without explicit copying

[André Hauser]

Dear forum,
I want to use bfd to update an existing ELF file, i.e. open a bfd,
perform some changes and save the file afterwards.
Is there a way of doing this without copying the source file? I found
only the two functions bfd_openw() and bfd_openr() for creating a new
resp. opening a bfd; calling bfd_make_writable() in conjunction with
bfd_openr() did not work, my object file wasn't updated after closing
the bfd. 

Thank you for your response
Andre




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Re: Change an object file without explicit copying

[H. J. Lu]

On Sun, Jul 07, 2002 at 08:00:55AM +0200, André Hauser wrote:
> Dear forum,
> I want to use bfd to update an existing ELF file, i.e. open a bfd,
> perform some changes and save the file afterwards.
> Is there a way of doing this without copying the source file? I found
> only the two functions bfd_openw() and bfd_openr() for creating a new
> resp. opening a bfd; calling bfd_make_writable() in conjunction with
> bfd_openr() did not work, my object file wasn't updated after closing
> the bfd. 
> 

Have you tried libelf?

H.J.

RE: Change an object file without explicit copying

[andre_hauser]

Hi H.J.,

I am using bfd because I need its functionality for performing relocations;
that's why I can't change to libelf.
In my actual program, a bfd(1) is opened for reading an ELF file and copied 
to a bfd(2) created with bfd_openw() (some of the object's details are being 
modified while doing this).
Then I close this recently created bfd(2) and copy it byte by byte 
(i.e. without using bfd) to another file(3), which serves as destination 
for its original file(2)'s relocated sections' contents.
I would be happy if I could open bfd(1) for changing, make a copy of it and then perform 
the relocation with these two objects resp. files.

Greetings André

 

> -----Original Message-----
> From: H. J. Lu [mailto:hjl@lucon.org]
> Sent: Sunday, July 07, 2002 4:36 PM
> To: André Hauser
> Cc: binutils@sources.redhat.com
> Subject: Re: Change an object file without explicit copying
> 
> 
> On Sun, Jul 07, 2002 at 08:00:55AM +0200, André Hauser wrote:
> > Dear forum,
> > I want to use bfd to update an existing ELF file, i.e. open a bfd,
> > perform some changes and save the file afterwards.
> > Is there a way of doing this without copying the source 
> file? I found
> > only the two functions bfd_openw() and bfd_openr() for 
> creating a new
> > resp. opening a bfd; calling bfd_make_writable() in conjunction with
> > bfd_openr() did not work, my object file wasn't updated 
> after closing
> > the bfd. 
> > 
> 
> Have you tried libelf?
> 
> H.J.
>