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>.
 



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172665 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 3 deletions

diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 4ae27a4adc..4bdc1dc253 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -2913,10 +2913,12 @@ static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
   // Traverse the contexts of Objective-C classes.
   if (ObjCInterfaceDecl *IFace = dyn_cast<ObjCInterfaceDecl>(Ctx)) {
     // Traverse categories.
-    for (ObjCCategoryDecl *Category = IFace->getCategoryList();
-         Category; Category = Category->getNextClassCategory()) {
+    for (ObjCInterfaceDecl::visible_categories_iterator
+           Cat = IFace->visible_categories_begin(),
+           CatEnd = IFace->visible_categories_end();
+         Cat != CatEnd; ++Cat) {
       ShadowContextRAII Shadow(Visited);
-      LookupVisibleDecls(Category, Result, QualifiedNameLookup, false,
+      LookupVisibleDecls(*Cat, Result, QualifiedNameLookup, false,
                          Consumer, Visited);
     }