Destroy MDNodes gracefully while deleting llvm context.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96609 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 1 deletions

diff --git a/lib/VMCore/LLVMContextImpl.h b/lib/VMCore/LLVMContextImpl.h
index 62491d8..85bbe4a 100644
--- a/lib/VMCore/LLVMContextImpl.h
+++ b/lib/VMCore/LLVMContextImpl.h
@@ -229,13 +229,23 @@ public:
       if (I->second->use_empty())
         delete I->second;
     }
-    MDNodeSet.clear();
     AlwaysOpaqueTy->dropRef();
     for (OpaqueTypesTy::iterator I = OpaqueTypes.begin(), E = OpaqueTypes.end();
         I != E; ++I) {
       (*I)->AbstractTypeUsers.clear();
       delete *I;
     }
+    // Destroy MDNode operands first.
+    for (FoldingSetIterator<MDNode> I = MDNodeSet.begin(), E = MDNodeSet.end();
+         I != E;) {
+      MDNode *N = &(*I);
+      ++I;
+      N->replaceAllOperandsWithNull();
+    }
+    while (!MDNodeSet.empty()) {
+      MDNode *N = &(*MDNodeSet.begin());
+      N->destroy();
+    }
   }
 };