Re: Why are dwarf2 symbols getting assigned hidden visibility?

[MFL Commissioner <mfl-commissioner at marino dot st>]

On 1/17/2011 8:29 PM, Andrew Haley wrote:
> libgcc_s is supposed to be backwards compatible in all cases, so this
> really shouldn't be a problem.  Having said that, there may be
> incompatibilities in your version.

Hi Andrew,
As I understand it, the problem is that the system libgcc (v4.1) isn't 
forwards compatible with the newly build compiler (v4.6).  The addition 
of Unwind_GetIPInfo came about 4 years ago, I guess version 4.1 is older 
than that.   As long as the object files from the new compiler get 
linked with the new libgcc_s, there's no problem, but if they get linked 
with an older libgcc_s, then some symbols might not be known.

> > /usr/lib/libgcc_s.so (NetBSD 5.1)
> > /usr/pkg/lib/libgcc_s.so (pkgsrc version)
> >
> > Dealing with multiple versions of libgcc_s seems painful....
>
> No more so than any other shared library, I would have thought.
>
> Andrew.

Well, in additional to the library that comes with the operating system 
which can't be removed, there could be multiple versions of gcc on the 
same system for any number of reasons.  Each may want to build it's own 
libgcc_s and perhaps place in the same directory.  No, I think libgcc_s 
has special challengers over a regular shared library.  Unless you mean 
port/pkgsrc versions that also compete with a system version, then it 
would be a similar problem.

John