Re: Tru64 non-virtual thunks multiply defined

[Ian Lance Taylor <iant at google dot com>]

"Peter O'Gorman" <pogma@thewrittenword.com> writes:

> When building qt-3.3.8 and wxGTk on Tru64 UNIX 5.1
> (alphaev67-dec-osf5.1) with gcc-4.2.4, we got linker failures about
> duplicate non-virtual thunks, e.g. from qt:
> /usr/ccs/bin/ld:
> .obj/release-shared-mt/qmotifdnd_x11.o: non-virtual thunk to QDragMoveEvent::~QDragMoveEvent(): multiply defined
> .obj/release-shared-mt/qmotifdnd_x11.o: non-virtual thunk to QDragMoveEvent::~QDragMoveEvent(): multiply defined
> .obj/release-shared-mt/qmotifdnd_x11.o: non-virtual thunk to QDragEnterEvent::~QDragEnterEvent(): multiply defined
> .obj/release-shared-mt/qmotifdnd_x11.o: non-virtual thunk to QDragEnterEvent::~QDragEnterEvent(): multiply defined
>
> This appears to be because the non-virtual thunks are not output weak on this
> platform, so, those that appear in multiple objects will cause linker errors
> like this (in the above case, there are _ZThn16_N14QDragMoveEventD0Ev and
> _ZThn16_N14QDragMoveEventD1Ev in both qdnd_x11.o and qmotifdnd_x11.o).
>
> Tru64 appears to have some weak symbol support, is there a reason that
> these thunks are not weak? 

Tru64 is not widely used by gcc developers.  I do see support for
generating weak symbols in the source code, but I don't know why it
isn't helping here.  This is most likely a bug somewhere.  Please
report it according to http://gcc.gnu.org/bugs.html .  Thanks.

This message would be more appropriate for the mailing list
gcc-help@gcc.gnu.org.  Please take any followups there.  Thanks.

Ian