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

3 files changed, 16 insertions, 11 deletions

diff --git a/lib/Serialization/ASTReaderDecl.cpp b/lib/Serialization/ASTReaderDecl.cpp
index 32179798ea..9f8268adee 100644
--- a/lib/Serialization/ASTReaderDecl.cpp
+++ b/lib/Serialization/ASTReaderDecl.cpp
@@ -2404,7 +2404,7 @@ namespace {
       if (Tail)
         ASTDeclReader::setNextObjCCategory(Tail, Cat);
       else
-        Interface->setCategoryList(Cat);
+        Interface->setCategoryListRaw(Cat);
       Tail = Cat;
     }
     
@@ -2419,13 +2419,15 @@ namespace {
         Tail(0) 
     {
       // Populate the name -> category map with the set of known categories.
-      for (ObjCCategoryDecl *Cat = Interface->getCategoryList(); Cat;
-           Cat = Cat->getNextClassCategory()) {
+      for (ObjCInterfaceDecl::known_categories_iterator
+             Cat = Interface->known_categories_begin(),
+             CatEnd = Interface->known_categories_end();
+           Cat != CatEnd; ++Cat) {
         if (Cat->getDeclName())
-          NameCategoryMap[Cat->getDeclName()] = Cat;
+          NameCategoryMap[Cat->getDeclName()] = *Cat;
         
         // Keep track of the tail of the category list.
-        Tail = Cat;
+        Tail = *Cat;
       }
     }
 
diff --git a/lib/Serialization/ASTWriter.cpp b/lib/Serialization/ASTWriter.cpp
index 67e03c2334..8c14b5f395 100644
--- a/lib/Serialization/ASTWriter.cpp
+++ b/lib/Serialization/ASTWriter.cpp
@@ -3238,10 +3238,12 @@ void ASTWriter::WriteObjCCategories() {
     Categories.push_back(0);
     
     // Add the categories.
-    for (ObjCCategoryDecl *Cat = Class->getCategoryList();
-         Cat; Cat = Cat->getNextClassCategory(), ++Size) {
-      assert(getDeclID(Cat) != 0 && "Bogus category");
-      AddDeclRef(Cat, Categories);
+    for (ObjCInterfaceDecl::known_categories_iterator
+           Cat = Class->known_categories_begin(),
+           CatEnd = Class->known_categories_end();
+         Cat != CatEnd; ++Cat, ++Size) {
+      assert(getDeclID(*Cat) != 0 && "Bogus category");
+      AddDeclRef(*Cat, Categories);
     }
     
     // Update the size.
diff --git a/lib/Serialization/ASTWriterDecl.cpp b/lib/Serialization/ASTWriterDecl.cpp
index bc92fb714a..7a57bad736 100644
--- a/lib/Serialization/ASTWriterDecl.cpp
+++ b/lib/Serialization/ASTWriterDecl.cpp
@@ -491,13 +491,14 @@ void ASTDeclWriter::VisitObjCInterfaceDecl(ObjCInterfaceDecl *D) {
            PEnd = Data.AllReferencedProtocols.end();
          P != PEnd; ++P)
       Writer.AddDeclRef(*P, Record);
+
     
-    if (ObjCCategoryDecl *Cat = D->getCategoryList()) {
+    if (ObjCCategoryDecl *Cat = D->getCategoryListRaw()) {
       // Ensure that we write out the set of categories for this class.
       Writer.ObjCClassesWithCategories.insert(D);
       
       // Make sure that the categories get serialized.
-      for (; Cat; Cat = Cat->getNextClassCategory())
+      for (; Cat; Cat = Cat->getNextClassCategoryRaw())
         (void)Writer.GetDeclRef(Cat);
     }
   }