- have public visibility
- have at most one back deployment version per-platform
- specify an introduced version for each platform with a back deployment version using @available
- have a back deployment version that is greater than the introduced version
- not have conflicting attributes like @_alwaysEmitIntoClient
Refactor to share code with type checking for @_originallyDefinedIn which has overlapping diagnostics.
This affects module interfaces, interface generation in sourcekitd, and
diagnostics. Also fixes a fixit that was assuming the 'OSX' spelling when
computing the source range to replace.
Resolves rdar://problem/64667960
We need this attribute to teach compiler to use a different name from the current
module name when generating runtime symbol names for a declaration. This is to serve
the workflow of refactoring a symbol from one library to another without breaking the existing
ABI.
This patch focuses on parsing and serializing the attribute, so @_originallyDefinedIn
will show up in AST, swiftinterface files and swiftmodule files.
rdar://55268186
