make CallGraphNode dtor abort if a node is deleted when there are still
references to it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101847 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/IPA/CallGraph.cpp b/lib/Analysis/IPA/CallGraph.cpp
index 8c43aa1..c59c31c 100644
--- a/lib/Analysis/IPA/CallGraph.cpp
+++ b/lib/Analysis/IPA/CallGraph.cpp
@@ -158,6 +158,7 @@
   // destroy - Release memory for the call graph
   virtual void destroy() {
     /// CallsExternalNode is not in the function map, delete it explicitly.
+    CallsExternalNode->allReferencesDropped();
     delete CallsExternalNode;
     CallsExternalNode = 0;
     CallGraph::destroy();
@@ -181,6 +182,14 @@
 void CallGraph::destroy() {
   if (FunctionMap.empty()) return;
   
+  // Reset all node's use counts to zero before deleting them to prevent an
+  // assertion from firing.
+#ifndef NDEBUG
+  for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
+       I != E; ++I)
+    I->second->allReferencesDropped();
+#endif
+  
   for (FunctionMapTy::iterator I = FunctionMap.begin(), E = FunctionMap.end();
       I != E; ++I)
     delete I->second;