PR33552: Distinguish between declarations that are owned by no module and
declarations that are owned but unconditionally visible.

This allows us to set declarations as visible even if they have a local owning
module, without losing information. In turn, that means that our Objective-C
support can keep on incorrectly assuming the "hidden" bit on the declaration is
the whole story with regard to name visibility. This will also be useful once
we support the C++ Modules TS export semantics.

Objective-C name visibility is still incorrect in any case where the "hidden"
bit is not the complete story: for instance, in Objective-C++ the set of
visible categories will be wrong during template instantiation, and with local
submodule visibility enabled it will be wrong when building modules. Fixing that
will require a major overhaul of how visibility is handled for Objective-C (and
particularly for categories).

llvm-svn: 306075
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 77ba6cf..a0594a0 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -278,12 +278,12 @@
   // FIXME: We shouldn't be changing the lexical context of declarations
   // imported from AST files.
   if (!isFromASTFile()) {
-    Hidden = cast<Decl>(DC)->Hidden && hasLocalOwningModuleStorage();
-    if (Hidden)
+    setModuleOwnershipKind(getModuleOwnershipKindForChildOf(DC));
+    if (hasOwningModule())
       setLocalOwningModule(cast<Decl>(DC)->getOwningModule());
   }
 
-  assert((!Hidden || getOwningModule()) &&
+  assert((!hasOwningModule() || getOwningModule()) &&
          "hidden declaration has no owning module");
 }