GCC 10.1 Released

> For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable.

OpenWRT is a whole OS-building SDK unto itself: a cross-compiler is bundled with it, is not a typical component found in a host OS, and cannot be trivially replaced (not least due to the fact that it's a heavily patched copy of GCC).