RFC: AccessController merge

[Andrew Haley]

Gary Benson writes:
 > Andrew Haley wrote:
 > > I'm a bit concerned about efficiency.  For one example: OK, we walk
 > > the stack -- we have to do that -- but we create a string for every
 > > method name , and the only purpose of doing so AFAICS is to compare
 > > it with "doPrivileged".  We then throw away all of those strings we
 > > so laboriously constructed...
 > 
 > I see what you mean.  Another thing is that if there is a doPrivileged
 > there then a chunk of the generated stack trace will be ignored.  I
 > guess Casey wanted the code he put in stacktrace.cc to be generic.
 > 
 > > I suppose this should go in, but we should study profile data and
 > > make efficiency improvments if required before release.
 > 
 > Should I commit now, or wait for other comments?

Commit this version, but don't go away and start something else!  We
need something decently efficient.

Andrew.