GCC, LLVM, and compiler plugins

Posted Jan 30, 2014 19:35 UTC (Thu) by DOT (subscriber, #58786)
In reply to: GCC, LLVM, and compiler plugins by vonbrand
Parent article: GCC, LLVM, and compiler plugins

A license can say that you may only use or distribute the program if you don't wear purple pajamas. It can't forbid your wearing of purple pajamas at all, but it can forbid using or distributing the program in that case. In the same way, it can put whatever restrictions on your use or distribution of the program in case you do it together with another, proprietary, program. This is not dependent on any standard definition of derivative work or any law whatsoever: it can attach any restrictions to the use of the program.

GCC, LLVM, and compiler plugins

Posted Jan 30, 2014 20:34 UTC (Thu) by vonbrand (subscriber, #4458) [Link] (1 responses)

Licenses like GPL operate in the range regulated by copyright law. If the PPL says the software can't be used unless wearing purple pajamas, that restriction is void as copyright doesn't cover use, only copying and distribution. Likewise, coyright covers copying of a particular work, not if it is shipped together with other stuff (unless it becomes a part of a greater whole, in which case you are talking about coyright on the collection as such). And I believe there are some "reasonableness" conditions in what the license might demand.

In what is wrongly called "software licenses" (which are really contracts) you can agree to more stringent conditions.

GCC, LLVM, and compiler plugins

Posted Jan 30, 2014 20:44 UTC (Thu) by DOT (subscriber, #58786) [Link]

Right, my mistake. Still, this only changes my argument slightly: a copyright license can still demand anything in return for giving you permission to copy or distribute. It may demand that you don't link it with proprietary software just like it may demand that you wear purple pajamas while doing the distributing.

This does restrict the power of the GPL: it cannot say anything about linking the program with a proprietary one on you own system. But it can say just fine that it considers such linking a BadThing, and it may not be distributed while it is a BadThing.