Re: Ian's solution [was: What hack in ld.so?]

[David Engel <dlengel@home.com>]

On Sat, Jan 30, 1999 at 10:40:33PM -0600, Gordon Matzigkeit wrote:
> There's been so much traffic on this thread, that I suspect most
> people have missed the fact that Ian Lance Taylor has analyzed and
> *solved* the problems with interaction between libtool and
> libc5-compat shared libraries.
> 
> I'm quoting and reposting his message so that it doesn't get lost in
> the shuffle.  Please read and understand this message before posting
> more flameage.

I am the Debian and upstream maintainer of the libc5 ld.so.  Ian's
patch will not be going in.  IMO, -rpath should not be used for any
libraries installed in standard, system locations (i.e. any place
listed in /etc/ld.so.conf).  -rpath should only be used when libraries
are installed in nonstandard locations.

FWIW, I cringed the first time I saw what RedHat had done.  They did
not foresee the evils of -rpath and the problems it would cause in the
libc5/libc6 transition.

David

> >>>>> Ian Lance Taylor writes:
> 
>  ILT> I just spent some time looking at the ld.so sources.
>  ILT> Interestingly, it seems to me that everything will work
>  ILT> correctly in the sources I was looking at.  That is because the
>  ILT> libc5 dynamic linker on my system (RedHat 5.2) was modified to
>  ILT> search the library cache before using the application's
>  ILT> DT_RPATH.
> 
>  ILT> I think that is a hack that Debian is missing: it is the final
>  ILT> hack to the libc5 dynamic linker to change the search path to
>  ILT> account for the moved shared libraries even when rpath is used.
>  ILT> I have appended the RedHat patch below.  This is to ld.so-1.9.5.
>  ILT> Of course, this will technically break the handling of DT_RPATH.
>  ILT> However, we've already determined that DT_RPATH binaries will
>  ILT> not work correctly anyhow, because the shared libraries were
>  ILT> moved.  So using this patch should not make us any worse off.
> 
> [...]
> 
>  ILT> Although I can not test this, I now believe that if you take a
>  ILT> libtool program, compile it on a libc5 Slackware and try to run
>  ILT> it on a RedHat 5.2 system, it will work.
> 
> His patch follows...

-- 
David Engel
dlengel@home.com