The SILGen testsuite consists of valid Swift code covering most language
features. We use these tests to verify that no unknown nodes are in the
file's libSyntax tree. That way we will (hopefully) catch any future
changes or additions to the language which are not implemented in
libSyntax.
These classes don't show up well in generated headers (rdar://problem/20855568),
can't actually be allocated from Objective-C (rdar://problem/17184317), and
make the story of "what is exposed to Objective-C" more complicated. Better
to just disallow them.
All classes are still "id-compatible" in that they can be converted to
AnyObject and passed to Objective-C, they secretly implement NSObjectProtocol
(via our SwiftObject root class), and their members can still be individually
exposed to Objective-C.
The frontend flag -disable-objc-attr-requires-foundation-module will disable
this requirement as well, which is still necessary for both the standard
library and a variety of tests I didn't feel like transforming.
Swift SVN r29760
This prevents us from seeing a less useful error message from SILGen
further down the line.
Also fix a bug where @objc without importing Foundation was not diagnosed
after the first top-level form. Some tests were relying on this behavior,
so fix those tests, either by splitting off the objc parts of the test, or
just by passing the -disable-objc-attr-requires-foundation-module flag.
Fixes <rdar://problem/20660270>.
Swift SVN r29359
