diff --git a/llvm/include/llvm/Support/YAMLParser.h b/llvm/include/llvm/Support/YAMLParser.h
--- a/llvm/include/llvm/Support/YAMLParser.h
+++ b/llvm/include/llvm/Support/YAMLParser.h
@@ -102,6 +102,8 @@
 
   void printError(Node *N, const Twine &Msg,
                   SourceMgr::DiagKind Kind = SourceMgr::DK_Error);
+  void printError(const SMRange &Range, const Twine &Msg,
+                  SourceMgr::DiagKind Kind = SourceMgr::DK_Error);
 
 private:
   friend class Document;
diff --git a/llvm/include/llvm/Support/YAMLTraits.h b/llvm/include/llvm/Support/YAMLTraits.h
--- a/llvm/include/llvm/Support/YAMLTraits.h
+++ b/llvm/include/llvm/Support/YAMLTraits.h
@@ -18,6 +18,7 @@
 #include "llvm/Support/Allocator.h"
 #include "llvm/Support/Endian.h"
 #include "llvm/Support/Regex.h"
+#include "llvm/Support/SMLoc.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/VersionTuple.h"
 #include "llvm/Support/YAMLParser.h"
@@ -1471,9 +1472,10 @@
 
     static bool classof(const MapHNode *) { return true; }
 
-    using NameToNode = StringMap<std::unique_ptr<HNode>>;
+    using NameToNodeAndLoc =
+        StringMap<std::pair<std::unique_ptr<HNode>, SMRange>>;
 
-    NameToNode Mapping;
+    NameToNodeAndLoc Mapping;
     SmallVector<std::string, 6> ValidKeys;
   };
 
@@ -1495,9 +1497,11 @@
   std::unique_ptr<Input::HNode> createHNodes(Node *node);
   void setError(HNode *hnode, const Twine &message);
   void setError(Node *node, const Twine &message);
+  void setError(const SMRange &Range, const Twine &message);
 
   void reportWarning(HNode *hnode, const Twine &message);
   void reportWarning(Node *hnode, const Twine &message);
+  void reportWarning(const SMRange &Range, const Twine &message);
 
 public:
   // These are only used by operator>>. They could be private
diff --git a/llvm/lib/Support/YAMLParser.cpp b/llvm/lib/Support/YAMLParser.cpp
--- a/llvm/lib/Support/YAMLParser.cpp
+++ b/llvm/lib/Support/YAMLParser.cpp
@@ -1774,7 +1774,11 @@
 bool Stream::failed() { return scanner->failed(); }
 
 void Stream::printError(Node *N, const Twine &Msg, SourceMgr::DiagKind Kind) {
-  SMRange Range = N ? N->getSourceRange() : SMRange();
+  printError(N ? N->getSourceRange() : SMRange(), Msg, Kind);
+}
+
+void Stream::printError(const SMRange &Range, const Twine &Msg,
+                        SourceMgr::DiagKind Kind) {
   scanner->printError(Range.Start, Kind, Msg, Range);
 }
 
diff --git a/llvm/lib/Support/YAMLTraits.cpp b/llvm/lib/Support/YAMLTraits.cpp
--- a/llvm/lib/Support/YAMLTraits.cpp
+++ b/llvm/lib/Support/YAMLTraits.cpp
@@ -175,7 +175,7 @@
     return false;
   }
   MN->ValidKeys.push_back(Key);
-  HNode *Value = MN->Mapping[Key].get();
+  HNode *Value = MN->Mapping[Key].first.get();
   if (!Value) {
     if (Required)
       setError(CurrentNode, Twine("missing required key '") + Key + "'");
@@ -201,12 +201,12 @@
     return;
   for (const auto &NN : MN->Mapping) {
     if (!is_contained(MN->ValidKeys, NN.first())) {
-      HNode *ReportNode = NN.second.get();
+      const SMRange &ReportLoc = NN.second.second;
       if (!AllowUnknownKeys) {
-        setError(ReportNode, Twine("unknown key '") + NN.first() + "'");
+        setError(ReportLoc, Twine("unknown key '") + NN.first() + "'");
         break;
       } else
-        reportWarning(ReportNode, Twine("unknown key '") + NN.first() + "'");
+        reportWarning(ReportLoc, Twine("unknown key '") + NN.first() + "'");
     }
   }
 }
@@ -378,11 +378,24 @@
   EC = make_error_code(errc::invalid_argument);
 }
 
+void Input::setError(const SMRange &range, const Twine &message) {
+  Strm->printError(range, message);
+  EC = make_error_code(errc::invalid_argument);
+}
+
 void Input::reportWarning(HNode *hnode, const Twine &message) {
   assert(hnode && "HNode must not be NULL");
   Strm->printError(hnode->_node, message, SourceMgr::DK_Warning);
 }
 
+void Input::reportWarning(Node *node, const Twine &message) {
+  Strm->printError(node, message, SourceMgr::DK_Warning);
+}
+
+void Input::reportWarning(const SMRange &range, const Twine &message) {
+  Strm->printError(range, message, SourceMgr::DK_Warning);
+}
+
 std::unique_ptr<Input::HNode> Input::createHNodes(Node *N) {
   SmallString<128> StringStorage;
   if (ScalarNode *SN = dyn_cast<ScalarNode>(N)) {
@@ -426,7 +439,8 @@
       auto ValueHNode = createHNodes(Value);
       if (EC)
         break;
-      mapHNode->Mapping[KeyStr] = std::move(ValueHNode);
+      mapHNode->Mapping[KeyStr] =
+          std::make_pair(std::move(ValueHNode), KeyNode->getSourceRange());
     }
     return std::move(mapHNode);
   } else if (isa<NullNode>(N)) {