PING Jan Nieuwenhuizen re libguile17

[Jan Nieuwenhuizen]

Brian Dessent:

> Note that the Cygwin gcc is not using --enable-fully-dynamic-string, it
> is using the patch in PR24196 which is a compromise between the
> pessimization of assuming fully dynamic strings and the optimization of
> assuming one global instance of _S_empty_rep_storage.

Hmm, so I should try a forward-patch of that for 4.1?  Can someone give
me some pointers about this?

> Also, I'm confused on another issue: if libguile exposes a C++ ABI then
> mixing 4.1 and 3.4 should be incompatible anyway

AFAIK, 3.4 broke its abi with earlier 3.x exactly because of providing a
3.x version that was abi-compatible with the (much stricter and
sometimes problematic) 4.x series.

> , regardless of PR24196,
> by the fact that there are so many g++ changes between those major
> versions.  However looking at the exports of the DLL I see no C++
> symbols.  But if libguile does not expose a C++ ABI then why does the
> PR24196-patched gcc cause it to work again?  Or is it that it uses C++
> internally and that is where the std::string-across-DLL-boundaries
> problem occurs?

libguile does not use C++.  As far as I understand, it is a problem that
is introduced while linking the dlls.

Jan.

-- 
Jan Nieuwenhuizen <janneke@gnu.org> | GNU LilyPond - The music typesetter
http://www.xs4all.nl/~jantien       | http://www.lilypond.org