Fix crasher when N->getElement(n) is NULL

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90572 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/VMCore/AsmWriter.cpp b/lib/VMCore/AsmWriter.cpp
index 1865402a65f6d04f4cf9f41631a2f18129dfe3fd..44095ca4e858b962153437485fc916fd926d2c59 100644 (file)
--- a/lib/VMCore/AsmWriter.cpp
+++ b/lib/VMCore/AsmWriter.cpp
@@ -698,7 +698,7 @@ void SlotTracker::processFunction() {
         if (MDNode *N = dyn_cast_or_null<MDNode>(I->getOperand(i))) {
           // Create a metadata slot only if N contains no instructions.
           for (unsigned n = 0, e = N->getNumElements(); n != e; ++n)
-            if (isa<Instruction>(N->getElement(n)))
+            if (N->getElement(n) && isa<Instruction>(N->getElement(n)))
               continue;
           CreateMetadataSlot(N);
         }