Re: [gold patch] Fix incremental update problems with shared objects and versioned symbols

[Ian Lance Taylor <iant at google dot com>]

Cary Coutant <ccoutant@google.com> writes:

> I've been thinking about how to fix this right, and I'm tending
> towards the belief that it's fine as is. In order to track the
> versions of defined symbols, I don't think it would be enough to use
> the version sections in the a.out, because those won't necessarily
> contain versions for all the symbols defined in shared libraries.
> Therefore, I'd have to record version definitions for the symbols in
> the incremental link info for each shared library. Once a full link
> has resolved all the symbols, though, the only danger in ignoring
> versions in subsequent incremental updates is that a changed file
> might explicitly reference a different version of a library entry
> point. I wonder what the likelihood is of that, and whether there
> might be easier ways of detecting that and forcing a fallback to a
> full link in that case.

I agree.

If you want to be careful, if an input file refers to a specific version
of a symbol, parse the version definitions in the executable.  If the
specific version does not appear in the executable already, force a full
link.

Ian