Fair enough. But do you stand by your assertion that something more abstract than literal header file text can be deserving of copyright but ABIs shouldn't? I'd like to know how near or far your line is from Oracle's, if only to have an example of where else the line could be drawn.

Yes, but that's the usual copyright rule isn't it? You can't get around copyright by search and replacing "Harry Potter" with "Barry Potter." And it's well understood that the less creative the expression, the less has to be different for a work not to infringe. I'd say changing a couple of parameter names wouldn't do it, but changing the syntax of the declarations surely would.