"You can't help but feel embarrassed for Oracle" on copyright claims
groklaw.net
groklaw.net
When you call a function, why should that function's copyright status have any bearing on the copyright status of your function? Because they're in the same file? What is a file?
One technicality is that until you compile the program, no copying is taking place, so the GPL can't apply to source code. The only argument against that I see is that you're intending for the copy to take place, which is as good as the copy actually taking place. But I have no idea. (OTOH, not many people try to avoid the GPL when sharing their source code anyway.)
If you have a billion-dollar idea that depends on the GPL working, you should probably hire a very good lawyer to advise you.