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, 5 insertions, 4 deletions

diff --git a/clang/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp
index b30c4e7b354..c66c7d01935 100644
--- a/clang/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/ObjCUnusedIVarsChecker.cpp
@@ -89,10 +89,11 @@ static void Scan(IvarUsageMap& M, const ObjCContainerDecl *D) {
       Scan(M, *I);
 
     // Scan the associated categories as well.
-    for (const ObjCCategoryDecl *CD =
-          ID->getClassInterface()->getCategoryList(); CD ;
-          CD = CD->getNextClassCategory()) {
-      if (const ObjCCategoryImplDecl *CID = CD->getImplementation())
+    for (ObjCInterfaceDecl::visible_categories_iterator
+           Cat = ID->getClassInterface()->visible_categories_begin(),
+           CatEnd = ID->getClassInterface()->visible_categories_end();
+         Cat != CatEnd; ++Cat) {
+      if (const ObjCCategoryImplDecl *CID = Cat->getImplementation())
         Scan(M, CID);
     }
   }