Gcc/10.2.0/gcc/Contributing
From Get docs
17 Contributing to GCC Development
If you would like to help pretest GCC releases to assure they work well, current development sources are available via Git (see http://gcc.gnu.org/git.html). Source and binary snapshots are also available for FTP; see http://gcc.gnu.org/snapshots.html.
If you would like to work on improvements to GCC, please read the advice at these URLs:
http://gcc.gnu.org/contribute.html http://gcc.gnu.org/contributewhy.html
for information on how to make useful contributions and avoid duplication of effort. Suggested projects are listed at http://gcc.gnu.org/projects/.