Re: optind

[Ian Lance Taylor <ian@wasabisystems.com>]

Baurjan Ismagulov <ibr@ata.cs.hun.edu.tr> writes:

> On Wed, Dec 10, 2003 at 05:12:56PM +0100, Andreas Schwab wrote:
> > It also exists in the executable, due to a COPY relocation.
> 
> Thanks much, I see it now!
> 
> And how should gdb know which one to use?

gdb should always use the one in the executable.  That is the one the
code in the shared library will also be using, because that is the
address will be in the GOT.

In principle, while debugging shared library code, gdb could observe
that there is a GOT relocation for optind, and look at the GOT table
in memory to decide which address to use.

Alternatively, gdb could guess that if there is a global variable in
the executable, that any reference to that global variable in the
shared library will refer to the one in the executable.  This will
normally be true, but will fail in cases where the library is
controlling visibility in any of various different ways.

In practice I have no idea what gdb actually does.

Ian