🚀 go-pugleaf

I'm helping someone who wants to make a Linux version of a big C++
program available. They are happy to distribute the executable under
relatively reasonable terms, but will not distribute the source and
are generally skittish about legal issues.

We are not clear on the licensing requirements of g++. In particular,
we're not sure what libraries might be linked into their code by g++
and what the terms on those libraries are. In general I understand the
LGPL and GPL - I just don't quite know what all is in g++.

Their intention is to only use iostream - no STL, nothing from libg++.
I checked the licensing on libio in libstdc++ and it looks like it has
no requirements on use:

    As a special exception, if you link this library with files
    compiled with a GNU compiler to produce an executable, this does not cause
    the resulting executable to be covered by the GNU General Public License.

Is that right? How do they verify that they are only incorporating
code with this license on it, and are not accidentally linking in
something that's under the LGPL or GPL? Also, are there any
requirements from linking with GNU libc itself?

Finally, what happens to the LGPL if you distribute something that's
dynamically linked agains the LGPLed libraries? Does that satisfy the
LGPL requirements?

Thanks
  Nelson