If a swift_name attribute’s context referred to the same declaration it was attached to, or a different declaration whose own swift_name referred to the current one, we would recurse infinitely and eventually overflow the stack. This commit makes us instead detect the cycle, diagnose it with a warning, and drop the affected declaration.
Fixes rdar://79370809.
When importing @compatibility_alias declarations check if underlying declaration
is generic and if so, forward generic environment and generic parameters (if any)
to newly created typealias declaration, otherwise there is going to be a mismatch
between type associated with typealias and its declaration which leads to crashes.
Resolves: rdar://problem/39849926
These aren't clang::TypedefNameDecls, but they should be treated like
them. There's not a great way to test this because the imported type
is a typealias and therefore not canonical, but fortunately debug info
preserves sugar.
Use the modern spelling for the nullability attributes in the test mock
headers. Currently, this was relying on the predefined macros from
clang to work. However, those are only available on Darwin targets.
This is needed to make the mock environments more portable.
