I'm new and wanting to help!

[Andrew Haley]

Joel Dice writes:
 > On Wed, 2 Aug 2006, Tom Tromey wrote:
 > 
 > > * The holy grail would be to allow a copying GC somehow.
 > >  We think this is very, very hard.
 > 
 > This is a topic near to my heart, since I'm implementing a Lisp 
 > interpreter using a copying GC.  The challenge is to accurately identify 
 > where the pointers are on the stack.  In my case, I maintain a 
 > thread-local linked list of pointer addresses, but this must be done 
 > manually and is obviously error-prone.  If GCC could do this (or the 
 > equivalent) automatically in a language-independent way, it would be a 
 > huge help for all front ends, VMs, and interpreters needing accurate GC.
 > 
 > Would it be possible to use debug information to determine the stack 
 > layout, similar to how DWARF is used for unwinding?

Yes, I think so.  But gcc might determine, for example, that one
object was at an offset from another and never save a pointer to the
second object at all.  It would be very hard to stop gcc doing this.  

Andrew.