Merge pull request #110 from lorentey/there-is-no-such-thing-as-an-implementation-only-import

[native] Stop using @_implementationOnly import in package configs

Author: lorentey

Sources/Atomics/Unmanaged extensions.swift

@@ -16,9 +16,17 @@ internal func _sa_retain_n(_ object: UnsafeMutableRawPointer, _ delta: UInt32)
 
 @_silgen_name("_sa_release_n")
 internal func _sa_release_n(_ object: UnsafeMutableRawPointer, _ delta: UInt32)
-#elseif ATOMICS_NATIVE_BUILTINS
-@_implementationOnly import _AtomicsShims
 #else
+// Note: with ATOMICS_NATIVE_BUILTINS, this file contains the last remaining
+// import of the shims module, and we only need it to get the declarations for
+// _sa_retain_n/_sa_release_n. The import is unfortunately still problematic;
+// these functions need to be moved into the stdlib or (preferably) we need
+// a compiler-level fix for https://github.com/apple/swift/issues/56105 to get rid
+// of it.
+//
+// Hiding the import using @_implementationOnly is not possible unless
+// Swift's library evolution dialect is enabled. (Which we cannot easily test
+// here.) Perhaps `internal import` will help work around this at some point.
 import _AtomicsShims
 #endif