Replace a FIXME with a comment describing why we did what we did
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@125757 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/DeclObjC.h b/include/clang/AST/DeclObjC.h
index 2ddb684..ddc680f 100644
--- a/include/clang/AST/DeclObjC.h
+++ b/include/clang/AST/DeclObjC.h
@@ -450,8 +450,11 @@
/// Protocols reference in both the @interface and class extensions.
ObjCList<ObjCProtocolDecl> AllReferencedProtocols;
- /// List of categories defined for this class.
- /// FIXME: Why is this a linked list??
+ /// \brief List of categories and class extensions defined for this class.
+ ///
+ /// Categories are stored as a linked list in the AST, since the categories
+ /// and class extensions come long after the initial interface declaration,
+ /// and we avoid dynamically-resized arrays in the AST whereever possible.
ObjCCategoryDecl *CategoryList;
/// IvarList - List of all ivars defined by this class; including class