[oe] Blackfin toolchain question

[Phil Blundell]

On Wed, 2009-11-11 at 22:27 +0000, Dmitry Eremin-Solenikov wrote:
> I'm currently trying to restore/update blackfin toolchain. One of the major problems I've stumbled upon
> are versioned scripts/export symbols. Basically there are lot's of software starting from g++ itself
> that have symbol versioning scripts. The problem is that blackfin arch prepends all symbols with underscore,
> thus breaking all that scripts.
> 
> My first intention was to follow the alsa-libs approach: handle all prefixing on package-per-package basis.
> However that would be a nigtmare.
> 
> My current intention (that at least partially works) is to make libtool (when it's used) generate correct
> versioning scripts and resort to package-per-package updating after that.
> 
> The problem comes from C++ world, where versioning script can contain unmangled name, but it's demangled
> name that should be prefixed with underscore.
> 
> So I have a bit hackish idea: maybe it's better to hack ld to accept scripts w/o underscores and prefix all
> symbols with it? This will eliminate most of changes. The question is if this patch is acceptable for OE?
> Does this approach sound too hackish?

How do other Blackfin folks deal with this issue?  It doesn't sound like
there is anything OE-specific about the problem you are facing, and I
would have thought that it is something that should be solved upstream
rather than with a local hack in OE.

Linker version scripts operate on symbol names, not on function names,
so I don't think that having the underscores automatically added here
would be appropriate.  

It is a little bit unfortunate that the Blackfin folks have decided to
put these underscores in their symbols.  The ELF gABI calls for symbol
names to be the same as C function names (i.e. no prefix) and, although
I guess the psABI is permitted to countermand that, the vast majority of
architectures do follow the gABI convention.  Underscore-prefixed symbol
names are fairly common in the a.out and COFF worlds but of course there
are no version scripts there so this issue does not arise.

p.