old intentional gcc bug?

[Brooks Moses]

Robert Dewar wrote:
> OK, interesting, thanks for info, I had always thought that this
> was purely conceptual.

One thing (which Erik didn't mention) that I noticed in the articles is 
that Ken said that in his implementation he also hacked the disassembler 
to cover up the evidence.

> Of course there is nothing special about open source/free software
> that makes such attacks more possible. On the contrary, since gcc
> can always be built using third party C compilers, it would be
> much easier to smoke out and eliminate any such behavior (indeed
> this example shows the merit of maintaining the property that gcc
> can be compiled by non-gcc compilers), although we have not been
> able to maintain that property for the Ada front end.

Indeed.  It would be interesting to confirm whether or not a copy of gcc 
bootstrapped with a non-gcc compiler matched byte-for-byte with a copy 
of gcc bootstrapped from gcc.  Not so much to look for intentional 
things like this, but to see whether the bootstrapping actually does 
achieve its goal of obtaining a result that's independent of the 
bootstrapping compiler.  Has anyone actually tried it?

- Brooks