MT-safe exceptions?

[H.J. Lu]

> This actually leads to another problem I ran a couple of days ago.
> Now there is C++ code in libgcc, and because gcc has many options
> that lead to binary incompability in C++ modules 
> (vtable-thunks at least), it is not practical to use other than 
> default options.  Other libraries like libstdc++ are easy to recompile 
> with desired options, but libgcc is not.
> 
> One might think using multilibs for this purpose, but the number
> of permutations will be quite high when combined to target
> specific multilibs.
> 

I believe vtable-thunks should be not easily changable. It
should be either on or off. Otherwise, it will lead many
problems as we have seen in EH and libio.

-- 
H.J. Lu (hjl@gnu.ai.mit.edu)