Re: [PATCH roland/arm-mcount] ARM: Disable compat mcount code when unneeded.

[Roland McGrath <roland@hack.frob.com>]

> Isn't this about objects built with old compilers (before GCC 4.4, when 
> __gnu_mcount_nc was introduced; arm*-*-linux-gnueabi support was added in 
> 4.1), which is generally supported, rather than objects built with old 
> library headers, which isn't?

I see.  I'd still like to find a way to exclude this code from
configurations that will never use it, i.e. a target for which there was
never a compiler that produced _mcount calls.  But perhaps there is no
"generic" way to achieve that.  I suppose I can just move it to a separate
file and let my configuration drop that file from sysdep-routines.

I think the ideal would be if we dropped it from the shared library (except
for a compat_symbol where needed, of course) and had it only in
libc_nonshared.a.  But I can't see a way to e.g. write _mcount in terms of
calling __gnu_mcount_nc (without breaking the profile so that it only
tracks _mcount itself as the callee), and I don't want to expose something
like __mcount_internal in the ABI just so that _mcount can call it.

Can you think of anything better?


Thanks,
Roland