Re: [MiNT] gcc-4.2.2-mint-20080127

[Vincent Rivière <vincent.riviere@freesbee.fr>]

Keith Scroggins wrote:
> sound/libsound.a(ym2612.o): In function 
> `MidiDriver_Emulated::MidiDriver_Emulated(Audio::Mixer*)':
> /home/Keith/scummvm-build/../scummvm/sound/softsynth/emumidi.h:60: 
> multiple definition of `non-virtual thunk to MidiDriver_Emulated::open()'
> sound/libsound.a(adlib.o):
> /home/Keith/scummvm-build/../scummvm/sound/softsynth/emumidi.h:60: first 
> defined here

I tried to cross-build ScummVM from the sources. Of course, it didn't 
link, because I don't have all the required libraries. However, it is 
enough to reproduce the virtual thunk problem !

I finally understood that `non-virtual thunk to 
MidiDriver_Emulated::open()' is simply the demangled name of a symbol 
(i.e. a function with a non-standard name)

An example of demangling using the c++filt tool:
$ m68k-atari-mint-c++filt __ZTv0_n12_N5Scumm9ScummFileD1Ev
virtual thunk to Scumm::ScummFile::~ScummFile()

That problematic symbols are defined with .globl in several files, thus 
the linker complains with multiple definitions.

ScummVM uses a complicated class tree with multiple inheritance and 
virtual inheritance (!), which is quite uncommon. The problem may be 
caused by a GCC bug, probably not related with the MiNT patch.

So... I think the first thing to do is to go to bed.

--
Vincent Rivière