[Bug c++/47218] [4.6.0 regression] C++ multiple definitions of non-virtual thunk problem

["davek at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47218

--- Comment #6 from Dave Korn <davek at gcc dot gnu.org> 2011-01-08 19:00:25 UTC ---
(In reply to comment #5)
> Bug is caused by the change at rev 167795 applied to fix PR46667.
> 
> http://gcc.gnu.org/viewcvs?view=revision&revision=167795

Full details at http://gcc.gnu.org/ml/gcc-patches/2011-01/msg00446.html:

>"  It turns out that resolve_unique_function() is not called at all for the
thunk function any more, where previously it was called from
assemble_start_function called from cgraph_expand_function.  This is because
gimple_expand_cfg() isn't called for these thunk functions; they are emitted
through a call chain that looks like:

> (gdb) bt
> #0  assemble_start_function (decl=0x7fe32f00,
>     fnname=0x7fe41860 "_ZThn4_N7FooBase3BarEv")
>     at /gnu/gcc/gcc-patched/gcc/varasm.c:1524
> #1  0x007aa73c in cgraph_expand_function (node=0x7ff80c30)
>     at /gnu/gcc/gcc-patched/gcc/cgraphunit.c:1328
> #2  0x007ad210 in cgraph_optimize ()
>     at /gnu/gcc/gcc-patched/gcc/cgraphunit.c:1567
> #3  0x007ad69a in cgraph_finalize_compilation_unit ()
>     at /gnu/gcc/gcc-patched/gcc/cgraphunit.c:1031
> #4  0x004ce825 in cp_write_global_declarations ()
>     at /gnu/gcc/gcc-patched/gcc/cp/decl2.c:3974
> #5  0x0080ed6d in toplev_main (argc=14, argv=0x5079f78)
>     at /gnu/gcc/gcc-patched/gcc/toplev.c:591
> #6  0x0060699f in main (argc=Cannot access memory at address 0x0
> ) at /gnu/gcc/gcc-patched/gcc/main.c:36  "

That's the main part of it.