Where can I get the source code to the compiler?

AFAIK, WindRiver uses a modified version of g++, which is licensed under the GNU GPL, requiring them to release the full source code. Where might I get a copy?

I am setting up my computer (running Ubuntu GNU/Linux) with the development environment, and I want to get a compiler working. I’ll leave being able to load the code onto the robot until next year.

EDIT:
Found it on FIRST Forge.

Here it is for anybody else who needs it:
http://firstforge.wpi.edu/sf/scm/do/viewRepository/projects.wpilib/scm.wpilibcpp

um, that’s WPILib source, not compiler source.

I know, I realized that what I needed was WPILIB, and that because they were using g++, I could just compile it with my standard compiler to see if it will build.