YAMLTraits.h: replace DenseMap that used a bad implementation of DenseMapInfo

for StringRef with a StringMap

The bug is that the empty key compares equal to the tombstone key.

Also added an assertion to DenseMap to catch similar bugs in future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187866 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/ADT/DenseMap.h

@@ -606,6 +606,9 @@ public:
   }
 
   void init(unsigned InitBuckets) {
+    assert(!KeyInfoT::isEqual(this->getEmptyKey(), this->getTombstoneKey()) &&
+           "Bad implementation of KeyInfoT: empty key and tombstone key "
+           "should be different");
     if (allocateBuckets(InitBuckets)) {
       this->BaseT::initEmpty();
     } else {