1 files changed, 11 insertions, 5 deletions
diff --git a/lib/Serialization/ASTReader.cpp b/lib/Serialization/ASTReader.cpp
index 639ef93fb6..a897d868e4 100644
--- a/lib/Serialization/ASTReader.cpp
+++ b/lib/Serialization/ASTReader.cpp
@@ -2223,13 +2223,15 @@ ASTReader::ReadASTBlock(ModuleFile &F) {
 
     case PENDING_IMPLICIT_INSTANTIATIONS:
       if (PendingInstantiations.size() % 2 != 0) {
+        Error("Invalid existing PendingInstantiations");
+        return Failure;
+      }
+
+      if (Record.size() % 2 != 0) {
         Error("Invalid PENDING_IMPLICIT_INSTANTIATIONS block");
         return Failure;
       }
-        
-      // Later lists of pending instantiations overwrite earlier ones.
-      // FIXME: This is most certainly wrong for modules.
-      PendingInstantiations.clear();
+
       for (unsigned I = 0, N = Record.size(); I != N; /* in loop */) {
         PendingInstantiations.push_back(getGlobalDeclID(F, Record[I++]));
         PendingInstantiations.push_back(
@@ -5592,7 +5594,11 @@ void ASTReader::ReadPendingInstantiations(
     ValueDecl *D = cast<ValueDecl>(GetDecl(PendingInstantiations[Idx++]));
     SourceLocation Loc
       = SourceLocation::getFromRawEncoding(PendingInstantiations[Idx++]);
-    Pending.push_back(std::make_pair(D, Loc));
+
+    // For modules, find out whether an instantiation already exists
+    if (!getContext().getLangOpts().Modules
+        || needPendingInstantiation(D))
+      Pending.push_back(std::make_pair(D, Loc));
   }  
   PendingInstantiations.clear();
 }