Z:gnu-www-ja-gcc-exception-3.1-faq--ee38e9-When we first considered addin/en

When we first considered adding a plugin infrastructure to GCC, we were deeply concerned about the possibility that someone would write a plugin that would merely save GCC's internal, low-level compilation data structures to disk. With that done, other software would be able to optimize or otherwise improve that code without being directly connected to GCC. It may have been difficult for us to argue that those programs should be subject to the GPL's copyleft, so we wanted to discourage these sorts of arrangements.