g++ serious bug in Ubuntu Lucid Lynx

["David R. Doucette" <ddoucette@xxxxxxxxxxxxxxxx>]

We just installed Lucid Lynx a few days ago, and have hit a fatal flaw 
with g++ that has forced us to stop the deployment and roll back the 
systems we could.

Structures in Lucid are now mapping differently than in the past, so we 
can no longer read our own files! Further, if any files are written by 
code produced by the new g++, they are corrupted.

The problem is that doubles are now being mapped onto a boundary 
divisible by 8 rather than a boundary divisible by 4, meaning that 
offsets change and structs get bigger.

I've attached a tar file showing the mapping on Jaunty, Karmic, and 
Lucid to show the change. This is a greatly simplified program that 
shows the problem, but it's happening in all of our C++ programs.

HELP!

System is Ubuntu 10.4 Lucid Lynx 64 bit.

David Doucette

Attachment: bug.tar
Description: Unix tar archive