1 files changed, 39 insertions, 9 deletions

diff --git a/include/clang/AST/DeclContextInternals.h b/include/clang/AST/DeclContextInternals.h
index 84f3698..9c626c8 100644
--- a/include/clang/AST/DeclContextInternals.h
+++ b/include/clang/AST/DeclContextInternals.h
@@ -18,6 +18,7 @@
 #include "clang/AST/DeclCXX.h"
 #include "clang/AST/DeclarationName.h"
 #include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/PointerIntPair.h"
 #include "llvm/ADT/PointerUnion.h"
 #include "llvm/ADT/SmallVector.h"
 #include <algorithm>
@@ -26,23 +27,29 @@ namespace clang {
 
 class DependentDiagnostic;
 
-/// StoredDeclsList - This is an array of decls optimized a common case of only
-/// containing one entry.
+/// \brief An array of decls optimized for the common case of only containing
+/// one entry.
 struct StoredDeclsList {
 
-  /// DeclsTy - When in vector form, this is what the Data pointer points to.
+  /// \brief When in vector form, this is what the Data pointer points to.
   typedef SmallVector<NamedDecl *, 4> DeclsTy;
 
+  /// \brief A collection of declarations, with a flag to indicate if we have
+  /// further external declarations.
+  typedef llvm::PointerIntPair<DeclsTy *, 1, bool> DeclsAndHasExternalTy;
+
   /// \brief The stored data, which will be either a pointer to a NamedDecl,
-  /// or a pointer to a vector.
-  llvm::PointerUnion<NamedDecl *, DeclsTy *> Data;
+  /// or a pointer to a vector with a flag to indicate if there are further
+  /// external declarations.
+  llvm::PointerUnion<NamedDecl*, DeclsAndHasExternalTy> Data;
 
 public:
   StoredDeclsList() {}
 
   StoredDeclsList(const StoredDeclsList &RHS) : Data(RHS.Data) {
     if (DeclsTy *RHSVec = RHS.getAsVector())
-      Data = new DeclsTy(*RHSVec);
+      Data = DeclsAndHasExternalTy(new DeclsTy(*RHSVec),
+                                   RHS.hasExternalDecls());
   }
 
   ~StoredDeclsList() {
@@ -56,7 +63,7 @@ public:
       delete Vector;
     Data = RHS.Data;
     if (DeclsTy *RHSVec = RHS.getAsVector())
-      Data = new DeclsTy(*RHSVec);
+      Data = DeclsAndHasExternalTy(new DeclsTy(*RHSVec), hasExternalDecls());
     return *this;
   }
 
@@ -66,8 +73,27 @@ public:
     return Data.dyn_cast<NamedDecl *>();
   }
 
+  DeclsAndHasExternalTy getAsVectorAndHasExternal() const {
+    return Data.dyn_cast<DeclsAndHasExternalTy>();
+  }
+
   DeclsTy *getAsVector() const {
-    return Data.dyn_cast<DeclsTy *>();
+    return getAsVectorAndHasExternal().getPointer();
+  }
+
+  bool hasExternalDecls() const {
+    return getAsVectorAndHasExternal().getInt();
+  }
+
+  void setHasExternalDecls() {
+    if (DeclsTy *Vec = getAsVector())
+      Data = DeclsAndHasExternalTy(Vec, true);
+    else {
+      DeclsTy *VT = new DeclsTy();
+      if (NamedDecl *OldD = getAsDecl())
+        VT->push_back(OldD);
+      Data = DeclsAndHasExternalTy(VT, true);
+    }
   }
 
   void setOnlyValue(NamedDecl *ND) {
@@ -110,6 +136,8 @@ public:
       Vec.erase(std::remove_if(Vec.begin(), Vec.end(),
                                std::mem_fun(&Decl::isFromASTFile)),
                 Vec.end());
+      // Don't have any external decls any more.
+      Data = DeclsAndHasExternalTy(&Vec, false);
     }
   }
 
@@ -165,12 +193,14 @@ public:
   /// not a redeclaration to merge it into the appropriate place in our list.
   ///
   void AddSubsequentDecl(NamedDecl *D) {
+    assert(!isNull() && "don't AddSubsequentDecl when we have no decls");
+
     // If this is the second decl added to the list, convert this to vector
     // form.
     if (NamedDecl *OldD = getAsDecl()) {
       DeclsTy *VT = new DeclsTy();
       VT->push_back(OldD);
-      Data = VT;
+      Data = DeclsAndHasExternalTy(VT, false);
     }
 
     DeclsTy &Vec = *getAsVector();