Rework the traversal of Objective-C categories and extensions to

consider (sub)module visibility.

The bulk of this change replaces myriad hand-rolled loops over the
linked list of Objective-C categories/extensions attached to an
interface declaration with loops using one of the four new category
iterator kinds:

  visible_categories_iterator: Iterates over all visible categories
  and extensions, hiding any that have their "hidden" bit set. This is
  by far the most commonly used iterator.

  known_categories_iterator: Iterates over all categories and
  extensions, ignoring the "hidden" bit. This tends to be used for
  redeclaration-like traversals.

  visible_extensions_iterator: Iterates over all visible extensions,
  hiding any that have their "hidden" bit set.

  known_extensions_iterator: Iterates over all extensions, whether
  they are visible to normal name lookup or not.

The effect of this change is that any uses of the visible_ iterators
will respect module-import visibility. See the new tests for examples.

Note that the old accessors for categories and extensions are gone;
there are *Raw() forms for some of them, for those (few) areas of the
compiler that have to manipulate the linked list of categories
directly. This is generally discouraged.

Part two of <rdar://problem/10634711>.
 

llvm-svn: 172665

1 files changed, 6 insertions, 4 deletions

diff --git a/clang/lib/ARCMigrate/TransProperties.cpp b/clang/lib/ARCMigrate/TransProperties.cpp
index 7196a54efc4..b6ddc43dd69 100644
--- a/clang/lib/ARCMigrate/TransProperties.cpp
+++ b/clang/lib/ARCMigrate/TransProperties.cpp
@@ -141,10 +141,12 @@ public:
 
     AtPropDeclsTy AtExtProps;
     // Look through extensions.
-    for (ObjCCategoryDecl *Cat = iface->getCategoryList();
-           Cat; Cat = Cat->getNextClassCategory())
-      if (Cat->IsClassExtension())
-        collectProperties(Cat, AtExtProps, &AtProps);
+    for (ObjCInterfaceDecl::visible_extensions_iterator
+           ext = iface->visible_extensions_begin(),
+           extEnd = iface->visible_extensions_end();
+         ext != extEnd; ++ext) {
+      collectProperties(*ext, AtExtProps, &AtProps);
+    }
 
     for (AtPropDeclsTy::iterator
            I = AtExtProps.begin(), E = AtExtProps.end(); I != E; ++I) {