Re: gnu linker/--no-as-needed?

[Peter Rosin]

[Technically this is a Libtool question, but I'll answer here anyway]

On 2014-01-08 07:58, Harlan Stenn wrote:
> I need configure to tell me if I can use --no-as-needed or --as-needed.
> 
> Right now we have been only using these flags if we're using GCC, and
> I've got a case (solaris) where gcc is calling the native loader, not
> gld.
> 
> The docs for LT_PATH_LD say that macro tries to find the path to the
> linker used by $CC, and whether it is the GNU linker.  But when I read
> the code for LT_PATH_LD it's sure not obvious to me how I can see if
> we're using a GNU linker.
> 
> Anybody have some suggestions for me?

The last thing LT_PATH_LD does is to expand _LT_PATH_LD_GNU, which runs the
linker with -v and looks for "GNU" or "with BFD" in the output and assumes
GNU ld if that is found. The result is stored in $with_gnu_ld (and a cache
variable).

If inside configure, I think it's fairly safe to just use $with_gnu_ld,
that's probably not going to change anytime soon.

Outside configure, evaluate something like:

.../libtool --config | grep '^with_gnu_ld='

> If it matters, we're using this because we've got a situation where we
> need to force linking libgcc_s, as it must be in the executable early
> enough; if we drop privileges it's too late to call dlopen().  That's
> not entirely accurate, but it's close enough.

Cheers,
Peter