Restoring authorship annotation for <orivej@yandex-team.ru>. Commit 2 of 2.

1 files changed, 1068 insertions, 1068 deletions

diff --git a/contrib/libs/llvm12/lib/Support/YAMLTraits.cpp b/contrib/libs/llvm12/lib/Support/YAMLTraits.cpp
index 7062248809..aa6163a761 100644
--- a/contrib/libs/llvm12/lib/Support/YAMLTraits.cpp
+++ b/contrib/libs/llvm12/lib/Support/YAMLTraits.cpp
@@ -1,383 +1,383 @@
-//===- lib/Support/YAMLTraits.cpp -----------------------------------------===// 
-// 
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 
-// See https://llvm.org/LICENSE.txt for license information. 
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 
-// 
-//===----------------------------------------------------------------------===// 
- 
-#include "llvm/Support/YAMLTraits.h" 
-#include "llvm/ADT/STLExtras.h" 
-#include "llvm/ADT/SmallString.h" 
-#include "llvm/ADT/StringExtras.h" 
-#include "llvm/ADT/StringRef.h" 
-#include "llvm/ADT/Twine.h" 
-#include "llvm/Support/Casting.h" 
-#include "llvm/Support/Errc.h" 
-#include "llvm/Support/ErrorHandling.h" 
-#include "llvm/Support/Format.h" 
-#include "llvm/Support/LineIterator.h" 
-#include "llvm/Support/MemoryBuffer.h" 
-#include "llvm/Support/Unicode.h" 
-#include "llvm/Support/YAMLParser.h" 
-#include "llvm/Support/raw_ostream.h" 
-#include <algorithm> 
-#include <cassert> 
-#include <cstdint> 
-#include <cstdlib> 
-#include <cstring> 
-#include <string> 
-#include <vector> 
- 
-using namespace llvm; 
-using namespace yaml; 
- 
-//===----------------------------------------------------------------------===// 
-//  IO 
-//===----------------------------------------------------------------------===// 
- 
-IO::IO(void *Context) : Ctxt(Context) {} 
- 
-IO::~IO() = default; 
- 
-void *IO::getContext() const { 
-  return Ctxt; 
-} 
- 
-void IO::setContext(void *Context) { 
-  Ctxt = Context; 
-} 
- 
+//===- lib/Support/YAMLTraits.cpp -----------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/YAMLTraits.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Errc.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/Format.h"
+#include "llvm/Support/LineIterator.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/Unicode.h"
+#include "llvm/Support/YAMLParser.h"
+#include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+#include <vector>
+
+using namespace llvm;
+using namespace yaml;
+
+//===----------------------------------------------------------------------===//
+//  IO
+//===----------------------------------------------------------------------===//
+
+IO::IO(void *Context) : Ctxt(Context) {}
+
+IO::~IO() = default;
+
+void *IO::getContext() const {
+  return Ctxt;
+}
+
+void IO::setContext(void *Context) {
+  Ctxt = Context;
+}
+
 void IO::setAllowUnknownKeys(bool Allow) {
   llvm_unreachable("Only supported for Input");
 }
 
-//===----------------------------------------------------------------------===// 
-//  Input 
-//===----------------------------------------------------------------------===// 
- 
-Input::Input(StringRef InputContent, void *Ctxt, 
-             SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt) 
-    : IO(Ctxt), Strm(new Stream(InputContent, SrcMgr, false, &EC)) { 
-  if (DiagHandler) 
-    SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt); 
-  DocIterator = Strm->begin(); 
-} 
- 
-Input::Input(MemoryBufferRef Input, void *Ctxt, 
-             SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt) 
-    : IO(Ctxt), Strm(new Stream(Input, SrcMgr, false, &EC)) { 
-  if (DiagHandler) 
-    SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt); 
-  DocIterator = Strm->begin(); 
-} 
- 
-Input::~Input() = default; 
- 
-std::error_code Input::error() { return EC; } 
- 
-// Pin the vtables to this file. 
-void Input::HNode::anchor() {} 
-void Input::EmptyHNode::anchor() {} 
-void Input::ScalarHNode::anchor() {} 
-void Input::MapHNode::anchor() {} 
-void Input::SequenceHNode::anchor() {} 
- 
-bool Input::outputting() const { 
-  return false; 
-} 
- 
-bool Input::setCurrentDocument() { 
-  if (DocIterator != Strm->end()) { 
-    Node *N = DocIterator->getRoot(); 
-    if (!N) { 
-      EC = make_error_code(errc::invalid_argument); 
-      return false; 
-    } 
- 
-    if (isa<NullNode>(N)) { 
-      // Empty files are allowed and ignored 
-      ++DocIterator; 
-      return setCurrentDocument(); 
-    } 
-    TopNode = createHNodes(N); 
-    CurrentNode = TopNode.get(); 
-    return true; 
-  } 
-  return false; 
-} 
- 
-bool Input::nextDocument() { 
-  return ++DocIterator != Strm->end(); 
-} 
- 
-const Node *Input::getCurrentNode() const { 
-  return CurrentNode ? CurrentNode->_node : nullptr; 
-} 
- 
-bool Input::mapTag(StringRef Tag, bool Default) { 
-  // CurrentNode can be null if setCurrentDocument() was unable to 
-  // parse the document because it was invalid or empty. 
-  if (!CurrentNode) 
-    return false; 
- 
-  std::string foundTag = CurrentNode->_node->getVerbatimTag(); 
-  if (foundTag.empty()) { 
-    // If no tag found and 'Tag' is the default, say it was found. 
-    return Default; 
-  } 
-  // Return true iff found tag matches supplied tag. 
-  return Tag.equals(foundTag); 
-} 
- 
-void Input::beginMapping() { 
-  if (EC) 
-    return; 
-  // CurrentNode can be null if the document is empty. 
-  MapHNode *MN = dyn_cast_or_null<MapHNode>(CurrentNode); 
-  if (MN) { 
-    MN->ValidKeys.clear(); 
-  } 
-} 
- 
-std::vector<StringRef> Input::keys() { 
-  MapHNode *MN = dyn_cast<MapHNode>(CurrentNode); 
-  std::vector<StringRef> Ret; 
-  if (!MN) { 
-    setError(CurrentNode, "not a mapping"); 
-    return Ret; 
-  } 
-  for (auto &P : MN->Mapping) 
-    Ret.push_back(P.first()); 
-  return Ret; 
-} 
- 
-bool Input::preflightKey(const char *Key, bool Required, bool, bool &UseDefault, 
-                         void *&SaveInfo) { 
-  UseDefault = false; 
-  if (EC) 
-    return false; 
- 
-  // CurrentNode is null for empty documents, which is an error in case required 
-  // nodes are present. 
-  if (!CurrentNode) { 
-    if (Required) 
-      EC = make_error_code(errc::invalid_argument); 
-    return false; 
-  } 
- 
-  MapHNode *MN = dyn_cast<MapHNode>(CurrentNode); 
-  if (!MN) { 
-    if (Required || !isa<EmptyHNode>(CurrentNode)) 
-      setError(CurrentNode, "not a mapping"); 
-    else 
-      UseDefault = true; 
-    return false; 
-  } 
-  MN->ValidKeys.push_back(Key); 
+//===----------------------------------------------------------------------===//
+//  Input
+//===----------------------------------------------------------------------===//
+
+Input::Input(StringRef InputContent, void *Ctxt,
+             SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt)
+    : IO(Ctxt), Strm(new Stream(InputContent, SrcMgr, false, &EC)) {
+  if (DiagHandler)
+    SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt);
+  DocIterator = Strm->begin();
+}
+
+Input::Input(MemoryBufferRef Input, void *Ctxt,
+             SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt)
+    : IO(Ctxt), Strm(new Stream(Input, SrcMgr, false, &EC)) {
+  if (DiagHandler)
+    SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt);
+  DocIterator = Strm->begin();
+}
+
+Input::~Input() = default;
+
+std::error_code Input::error() { return EC; }
+
+// Pin the vtables to this file.
+void Input::HNode::anchor() {}
+void Input::EmptyHNode::anchor() {}
+void Input::ScalarHNode::anchor() {}
+void Input::MapHNode::anchor() {}
+void Input::SequenceHNode::anchor() {}
+
+bool Input::outputting() const {
+  return false;
+}
+
+bool Input::setCurrentDocument() {
+  if (DocIterator != Strm->end()) {
+    Node *N = DocIterator->getRoot();
+    if (!N) {
+      EC = make_error_code(errc::invalid_argument);
+      return false;
+    }
+
+    if (isa<NullNode>(N)) {
+      // Empty files are allowed and ignored
+      ++DocIterator;
+      return setCurrentDocument();
+    }
+    TopNode = createHNodes(N);
+    CurrentNode = TopNode.get();
+    return true;
+  }
+  return false;
+}
+
+bool Input::nextDocument() {
+  return ++DocIterator != Strm->end();
+}
+
+const Node *Input::getCurrentNode() const {
+  return CurrentNode ? CurrentNode->_node : nullptr;
+}
+
+bool Input::mapTag(StringRef Tag, bool Default) {
+  // CurrentNode can be null if setCurrentDocument() was unable to
+  // parse the document because it was invalid or empty.
+  if (!CurrentNode)
+    return false;
+
+  std::string foundTag = CurrentNode->_node->getVerbatimTag();
+  if (foundTag.empty()) {
+    // If no tag found and 'Tag' is the default, say it was found.
+    return Default;
+  }
+  // Return true iff found tag matches supplied tag.
+  return Tag.equals(foundTag);
+}
+
+void Input::beginMapping() {
+  if (EC)
+    return;
+  // CurrentNode can be null if the document is empty.
+  MapHNode *MN = dyn_cast_or_null<MapHNode>(CurrentNode);
+  if (MN) {
+    MN->ValidKeys.clear();
+  }
+}
+
+std::vector<StringRef> Input::keys() {
+  MapHNode *MN = dyn_cast<MapHNode>(CurrentNode);
+  std::vector<StringRef> Ret;
+  if (!MN) {
+    setError(CurrentNode, "not a mapping");
+    return Ret;
+  }
+  for (auto &P : MN->Mapping)
+    Ret.push_back(P.first());
+  return Ret;
+}
+
+bool Input::preflightKey(const char *Key, bool Required, bool, bool &UseDefault,
+                         void *&SaveInfo) {
+  UseDefault = false;
+  if (EC)
+    return false;
+
+  // CurrentNode is null for empty documents, which is an error in case required
+  // nodes are present.
+  if (!CurrentNode) {
+    if (Required)
+      EC = make_error_code(errc::invalid_argument);
+    return false;
+  }
+
+  MapHNode *MN = dyn_cast<MapHNode>(CurrentNode);
+  if (!MN) {
+    if (Required || !isa<EmptyHNode>(CurrentNode))
+      setError(CurrentNode, "not a mapping");
+    else
+      UseDefault = true;
+    return false;
+  }
+  MN->ValidKeys.push_back(Key);
   HNode *Value = MN->Mapping[Key].first.get();
-  if (!Value) { 
-    if (Required) 
-      setError(CurrentNode, Twine("missing required key '") + Key + "'"); 
-    else 
-      UseDefault = true; 
-    return false; 
-  } 
-  SaveInfo = CurrentNode; 
-  CurrentNode = Value; 
-  return true; 
-} 
- 
-void Input::postflightKey(void *saveInfo) { 
-  CurrentNode = reinterpret_cast<HNode *>(saveInfo); 
-} 
- 
-void Input::endMapping() { 
-  if (EC) 
-    return; 
-  // CurrentNode can be null if the document is empty. 
-  MapHNode *MN = dyn_cast_or_null<MapHNode>(CurrentNode); 
-  if (!MN) 
-    return; 
-  for (const auto &NN : MN->Mapping) { 
-    if (!is_contained(MN->ValidKeys, NN.first())) { 
+  if (!Value) {
+    if (Required)
+      setError(CurrentNode, Twine("missing required key '") + Key + "'");
+    else
+      UseDefault = true;
+    return false;
+  }
+  SaveInfo = CurrentNode;
+  CurrentNode = Value;
+  return true;
+}
+
+void Input::postflightKey(void *saveInfo) {
+  CurrentNode = reinterpret_cast<HNode *>(saveInfo);
+}
+
+void Input::endMapping() {
+  if (EC)
+    return;
+  // CurrentNode can be null if the document is empty.
+  MapHNode *MN = dyn_cast_or_null<MapHNode>(CurrentNode);
+  if (!MN)
+    return;
+  for (const auto &NN : MN->Mapping) {
+    if (!is_contained(MN->ValidKeys, NN.first())) {
       const SMRange &ReportLoc = NN.second.second;
       if (!AllowUnknownKeys) {
         setError(ReportLoc, Twine("unknown key '") + NN.first() + "'");
         break;
       } else
         reportWarning(ReportLoc, Twine("unknown key '") + NN.first() + "'");
-    } 
-  } 
-} 
- 
-void Input::beginFlowMapping() { beginMapping(); } 
- 
-void Input::endFlowMapping() { endMapping(); } 
- 
-unsigned Input::beginSequence() { 
-  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) 
-    return SQ->Entries.size(); 
-  if (isa<EmptyHNode>(CurrentNode)) 
-    return 0; 
-  // Treat case where there's a scalar "null" value as an empty sequence. 
-  if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) { 
-    if (isNull(SN->value())) 
-      return 0; 
-  } 
-  // Any other type of HNode is an error. 
-  setError(CurrentNode, "not a sequence"); 
-  return 0; 
-} 
- 
-void Input::endSequence() { 
-} 
- 
-bool Input::preflightElement(unsigned Index, void *&SaveInfo) { 
-  if (EC) 
-    return false; 
-  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) { 
-    SaveInfo = CurrentNode; 
-    CurrentNode = SQ->Entries[Index].get(); 
-    return true; 
-  } 
-  return false; 
-} 
- 
-void Input::postflightElement(void *SaveInfo) { 
-  CurrentNode = reinterpret_cast<HNode *>(SaveInfo); 
-} 
- 
-unsigned Input::beginFlowSequence() { return beginSequence(); } 
- 
-bool Input::preflightFlowElement(unsigned index, void *&SaveInfo) { 
-  if (EC) 
-    return false; 
-  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) { 
-    SaveInfo = CurrentNode; 
-    CurrentNode = SQ->Entries[index].get(); 
-    return true; 
-  } 
-  return false; 
-} 
- 
-void Input::postflightFlowElement(void *SaveInfo) { 
-  CurrentNode = reinterpret_cast<HNode *>(SaveInfo); 
-} 
- 
-void Input::endFlowSequence() { 
-} 
- 
-void Input::beginEnumScalar() { 
-  ScalarMatchFound = false; 
-} 
- 
-bool Input::matchEnumScalar(const char *Str, bool) { 
-  if (ScalarMatchFound) 
-    return false; 
-  if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) { 
-    if (SN->value().equals(Str)) { 
-      ScalarMatchFound = true; 
-      return true; 
-    } 
-  } 
-  return false; 
-} 
- 
-bool Input::matchEnumFallback() { 
-  if (ScalarMatchFound) 
-    return false; 
-  ScalarMatchFound = true; 
-  return true; 
-} 
- 
-void Input::endEnumScalar() { 
-  if (!ScalarMatchFound) { 
-    setError(CurrentNode, "unknown enumerated scalar"); 
-  } 
-} 
- 
-bool Input::beginBitSetScalar(bool &DoClear) { 
-  BitValuesUsed.clear(); 
-  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) { 
-    BitValuesUsed.insert(BitValuesUsed.begin(), SQ->Entries.size(), false); 
-  } else { 
-    setError(CurrentNode, "expected sequence of bit values"); 
-  } 
-  DoClear = true; 
-  return true; 
-} 
- 
-bool Input::bitSetMatch(const char *Str, bool) { 
-  if (EC) 
-    return false; 
-  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) { 
-    unsigned Index = 0; 
-    for (auto &N : SQ->Entries) { 
-      if (ScalarHNode *SN = dyn_cast<ScalarHNode>(N.get())) { 
-        if (SN->value().equals(Str)) { 
-          BitValuesUsed[Index] = true; 
-          return true; 
-        } 
-      } else { 
-        setError(CurrentNode, "unexpected scalar in sequence of bit values"); 
-      } 
-      ++Index; 
-    } 
-  } else { 
-    setError(CurrentNode, "expected sequence of bit values"); 
-  } 
-  return false; 
-} 
- 
-void Input::endBitSetScalar() { 
-  if (EC) 
-    return; 
-  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) { 
-    assert(BitValuesUsed.size() == SQ->Entries.size()); 
-    for (unsigned i = 0; i < SQ->Entries.size(); ++i) { 
-      if (!BitValuesUsed[i]) { 
-        setError(SQ->Entries[i].get(), "unknown bit value"); 
-        return; 
-      } 
-    } 
-  } 
-} 
- 
-void Input::scalarString(StringRef &S, QuotingType) { 
-  if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) { 
-    S = SN->value(); 
-  } else { 
-    setError(CurrentNode, "unexpected scalar"); 
-  } 
-} 
- 
-void Input::blockScalarString(StringRef &S) { scalarString(S, QuotingType::None); } 
- 
-void Input::scalarTag(std::string &Tag) { 
-  Tag = CurrentNode->_node->getVerbatimTag(); 
-} 
- 
-void Input::setError(HNode *hnode, const Twine &message) { 
-  assert(hnode && "HNode must not be NULL"); 
-  setError(hnode->_node, message); 
-} 
- 
-NodeKind Input::getNodeKind() { 
-  if (isa<ScalarHNode>(CurrentNode)) 
-    return NodeKind::Scalar; 
-  else if (isa<MapHNode>(CurrentNode)) 
-    return NodeKind::Map; 
-  else if (isa<SequenceHNode>(CurrentNode)) 
-    return NodeKind::Sequence; 
-  llvm_unreachable("Unsupported node kind"); 
-} 
- 
-void Input::setError(Node *node, const Twine &message) { 
-  Strm->printError(node, message); 
-  EC = make_error_code(errc::invalid_argument); 
-} 
- 
+    }
+  }
+}
+
+void Input::beginFlowMapping() { beginMapping(); }
+
+void Input::endFlowMapping() { endMapping(); }
+
+unsigned Input::beginSequence() {
+  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode))
+    return SQ->Entries.size();
+  if (isa<EmptyHNode>(CurrentNode))
+    return 0;
+  // Treat case where there's a scalar "null" value as an empty sequence.
+  if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
+    if (isNull(SN->value()))
+      return 0;
+  }
+  // Any other type of HNode is an error.
+  setError(CurrentNode, "not a sequence");
+  return 0;
+}
+
+void Input::endSequence() {
+}
+
+bool Input::preflightElement(unsigned Index, void *&SaveInfo) {
+  if (EC)
+    return false;
+  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
+    SaveInfo = CurrentNode;
+    CurrentNode = SQ->Entries[Index].get();
+    return true;
+  }
+  return false;
+}
+
+void Input::postflightElement(void *SaveInfo) {
+  CurrentNode = reinterpret_cast<HNode *>(SaveInfo);
+}
+
+unsigned Input::beginFlowSequence() { return beginSequence(); }
+
+bool Input::preflightFlowElement(unsigned index, void *&SaveInfo) {
+  if (EC)
+    return false;
+  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
+    SaveInfo = CurrentNode;
+    CurrentNode = SQ->Entries[index].get();
+    return true;
+  }
+  return false;
+}
+
+void Input::postflightFlowElement(void *SaveInfo) {
+  CurrentNode = reinterpret_cast<HNode *>(SaveInfo);
+}
+
+void Input::endFlowSequence() {
+}
+
+void Input::beginEnumScalar() {
+  ScalarMatchFound = false;
+}
+
+bool Input::matchEnumScalar(const char *Str, bool) {
+  if (ScalarMatchFound)
+    return false;
+  if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
+    if (SN->value().equals(Str)) {
+      ScalarMatchFound = true;
+      return true;
+    }
+  }
+  return false;
+}
+
+bool Input::matchEnumFallback() {
+  if (ScalarMatchFound)
+    return false;
+  ScalarMatchFound = true;
+  return true;
+}
+
+void Input::endEnumScalar() {
+  if (!ScalarMatchFound) {
+    setError(CurrentNode, "unknown enumerated scalar");
+  }
+}
+
+bool Input::beginBitSetScalar(bool &DoClear) {
+  BitValuesUsed.clear();
+  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
+    BitValuesUsed.insert(BitValuesUsed.begin(), SQ->Entries.size(), false);
+  } else {
+    setError(CurrentNode, "expected sequence of bit values");
+  }
+  DoClear = true;
+  return true;
+}
+
+bool Input::bitSetMatch(const char *Str, bool) {
+  if (EC)
+    return false;
+  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
+    unsigned Index = 0;
+    for (auto &N : SQ->Entries) {
+      if (ScalarHNode *SN = dyn_cast<ScalarHNode>(N.get())) {
+        if (SN->value().equals(Str)) {
+          BitValuesUsed[Index] = true;
+          return true;
+        }
+      } else {
+        setError(CurrentNode, "unexpected scalar in sequence of bit values");
+      }
+      ++Index;
+    }
+  } else {
+    setError(CurrentNode, "expected sequence of bit values");
+  }
+  return false;
+}
+
+void Input::endBitSetScalar() {
+  if (EC)
+    return;
+  if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
+    assert(BitValuesUsed.size() == SQ->Entries.size());
+    for (unsigned i = 0; i < SQ->Entries.size(); ++i) {
+      if (!BitValuesUsed[i]) {
+        setError(SQ->Entries[i].get(), "unknown bit value");
+        return;
+      }
+    }
+  }
+}
+
+void Input::scalarString(StringRef &S, QuotingType) {
+  if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
+    S = SN->value();
+  } else {
+    setError(CurrentNode, "unexpected scalar");
+  }
+}
+
+void Input::blockScalarString(StringRef &S) { scalarString(S, QuotingType::None); }
+
+void Input::scalarTag(std::string &Tag) {
+  Tag = CurrentNode->_node->getVerbatimTag();
+}
+
+void Input::setError(HNode *hnode, const Twine &message) {
+  assert(hnode && "HNode must not be NULL");
+  setError(hnode->_node, message);
+}
+
+NodeKind Input::getNodeKind() {
+  if (isa<ScalarHNode>(CurrentNode))
+    return NodeKind::Scalar;
+  else if (isa<MapHNode>(CurrentNode))
+    return NodeKind::Map;
+  else if (isa<SequenceHNode>(CurrentNode))
+    return NodeKind::Sequence;
+  llvm_unreachable("Unsupported node kind");
+}
+
+void Input::setError(Node *node, const Twine &message) {
+  Strm->printError(node, message);
+  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);
@@ -396,718 +396,718 @@ 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)) { 
-    StringRef KeyStr = SN->getValue(StringStorage); 
-    if (!StringStorage.empty()) { 
-      // Copy string to permanent storage 
-      KeyStr = StringStorage.str().copy(StringAllocator); 
-    } 
-    return std::make_unique<ScalarHNode>(N, KeyStr); 
-  } else if (BlockScalarNode *BSN = dyn_cast<BlockScalarNode>(N)) { 
-    StringRef ValueCopy = BSN->getValue().copy(StringAllocator); 
-    return std::make_unique<ScalarHNode>(N, ValueCopy); 
-  } else if (SequenceNode *SQ = dyn_cast<SequenceNode>(N)) { 
-    auto SQHNode = std::make_unique<SequenceHNode>(N); 
-    for (Node &SN : *SQ) { 
-      auto Entry = createHNodes(&SN); 
-      if (EC) 
-        break; 
-      SQHNode->Entries.push_back(std::move(Entry)); 
-    } 
-    return std::move(SQHNode); 
-  } else if (MappingNode *Map = dyn_cast<MappingNode>(N)) { 
-    auto mapHNode = std::make_unique<MapHNode>(N); 
-    for (KeyValueNode &KVN : *Map) { 
-      Node *KeyNode = KVN.getKey(); 
-      ScalarNode *Key = dyn_cast_or_null<ScalarNode>(KeyNode); 
-      Node *Value = KVN.getValue(); 
-      if (!Key || !Value) { 
-        if (!Key) 
-          setError(KeyNode, "Map key must be a scalar"); 
-        if (!Value) 
-          setError(KeyNode, "Map value must not be empty"); 
-        break; 
-      } 
-      StringStorage.clear(); 
-      StringRef KeyStr = Key->getValue(StringStorage); 
-      if (!StringStorage.empty()) { 
-        // Copy string to permanent storage 
-        KeyStr = StringStorage.str().copy(StringAllocator); 
-      } 
-      auto ValueHNode = createHNodes(Value); 
-      if (EC) 
-        break; 
+std::unique_ptr<Input::HNode> Input::createHNodes(Node *N) {
+  SmallString<128> StringStorage;
+  if (ScalarNode *SN = dyn_cast<ScalarNode>(N)) {
+    StringRef KeyStr = SN->getValue(StringStorage);
+    if (!StringStorage.empty()) {
+      // Copy string to permanent storage
+      KeyStr = StringStorage.str().copy(StringAllocator);
+    }
+    return std::make_unique<ScalarHNode>(N, KeyStr);
+  } else if (BlockScalarNode *BSN = dyn_cast<BlockScalarNode>(N)) {
+    StringRef ValueCopy = BSN->getValue().copy(StringAllocator);
+    return std::make_unique<ScalarHNode>(N, ValueCopy);
+  } else if (SequenceNode *SQ = dyn_cast<SequenceNode>(N)) {
+    auto SQHNode = std::make_unique<SequenceHNode>(N);
+    for (Node &SN : *SQ) {
+      auto Entry = createHNodes(&SN);
+      if (EC)
+        break;
+      SQHNode->Entries.push_back(std::move(Entry));
+    }
+    return std::move(SQHNode);
+  } else if (MappingNode *Map = dyn_cast<MappingNode>(N)) {
+    auto mapHNode = std::make_unique<MapHNode>(N);
+    for (KeyValueNode &KVN : *Map) {
+      Node *KeyNode = KVN.getKey();
+      ScalarNode *Key = dyn_cast_or_null<ScalarNode>(KeyNode);
+      Node *Value = KVN.getValue();
+      if (!Key || !Value) {
+        if (!Key)
+          setError(KeyNode, "Map key must be a scalar");
+        if (!Value)
+          setError(KeyNode, "Map value must not be empty");
+        break;
+      }
+      StringStorage.clear();
+      StringRef KeyStr = Key->getValue(StringStorage);
+      if (!StringStorage.empty()) {
+        // Copy string to permanent storage
+        KeyStr = StringStorage.str().copy(StringAllocator);
+      }
+      auto ValueHNode = createHNodes(Value);
+      if (EC)
+        break;
       mapHNode->Mapping[KeyStr] =
           std::make_pair(std::move(ValueHNode), KeyNode->getSourceRange());
-    } 
-    return std::move(mapHNode); 
-  } else if (isa<NullNode>(N)) { 
-    return std::make_unique<EmptyHNode>(N); 
-  } else { 
-    setError(N, "unknown node kind"); 
-    return nullptr; 
-  } 
-} 
- 
-void Input::setError(const Twine &Message) { 
-  setError(CurrentNode, Message); 
-} 
- 
+    }
+    return std::move(mapHNode);
+  } else if (isa<NullNode>(N)) {
+    return std::make_unique<EmptyHNode>(N);
+  } else {
+    setError(N, "unknown node kind");
+    return nullptr;
+  }
+}
+
+void Input::setError(const Twine &Message) {
+  setError(CurrentNode, Message);
+}
+
 void Input::setAllowUnknownKeys(bool Allow) { AllowUnknownKeys = Allow; }
 
-bool Input::canElideEmptySequence() { 
-  return false; 
-} 
- 
-//===----------------------------------------------------------------------===// 
-//  Output 
-//===----------------------------------------------------------------------===// 
- 
-Output::Output(raw_ostream &yout, void *context, int WrapColumn) 
-    : IO(context), Out(yout), WrapColumn(WrapColumn) {} 
- 
-Output::~Output() = default; 
- 
-bool Output::outputting() const { 
-  return true; 
-} 
- 
-void Output::beginMapping() { 
-  StateStack.push_back(inMapFirstKey); 
-  PaddingBeforeContainer = Padding; 
-  Padding = "\n"; 
-} 
- 
-bool Output::mapTag(StringRef Tag, bool Use) { 
-  if (Use) { 
-    // If this tag is being written inside a sequence we should write the start 
-    // of the sequence before writing the tag, otherwise the tag won't be 
-    // attached to the element in the sequence, but rather the sequence itself. 
-    bool SequenceElement = false; 
-    if (StateStack.size() > 1) { 
-      auto &E = StateStack[StateStack.size() - 2]; 
-      SequenceElement = inSeqAnyElement(E) || inFlowSeqAnyElement(E); 
-    } 
-    if (SequenceElement && StateStack.back() == inMapFirstKey) { 
-      newLineCheck(); 
-    } else { 
-      output(" "); 
-    } 
-    output(Tag); 
-    if (SequenceElement) { 
-      // If we're writing the tag during the first element of a map, the tag 
-      // takes the place of the first element in the sequence. 
-      if (StateStack.back() == inMapFirstKey) { 
-        StateStack.pop_back(); 
-        StateStack.push_back(inMapOtherKey); 
-      } 
-      // Tags inside maps in sequences should act as keys in the map from a 
-      // formatting perspective, so we always want a newline in a sequence. 
-      Padding = "\n"; 
-    } 
-  } 
-  return Use; 
-} 
- 
-void Output::endMapping() { 
-  // If we did not map anything, we should explicitly emit an empty map 
-  if (StateStack.back() == inMapFirstKey) { 
-    Padding = PaddingBeforeContainer; 
-    newLineCheck(); 
-    output("{}"); 
-    Padding = "\n"; 
-  } 
-  StateStack.pop_back(); 
-} 
- 
-std::vector<StringRef> Output::keys() { 
-  report_fatal_error("invalid call"); 
-} 
- 
-bool Output::preflightKey(const char *Key, bool Required, bool SameAsDefault, 
-                          bool &UseDefault, void *&) { 
-  UseDefault = false; 
-  if (Required || !SameAsDefault || WriteDefaultValues) { 
-    auto State = StateStack.back(); 
-    if (State == inFlowMapFirstKey || State == inFlowMapOtherKey) { 
-      flowKey(Key); 
-    } else { 
-      newLineCheck(); 
-      paddedKey(Key); 
-    } 
-    return true; 
-  } 
-  return false; 
-} 
- 
-void Output::postflightKey(void *) { 
-  if (StateStack.back() == inMapFirstKey) { 
-    StateStack.pop_back(); 
-    StateStack.push_back(inMapOtherKey); 
-  } else if (StateStack.back() == inFlowMapFirstKey) { 
-    StateStack.pop_back(); 
-    StateStack.push_back(inFlowMapOtherKey); 
-  } 
-} 
- 
-void Output::beginFlowMapping() { 
-  StateStack.push_back(inFlowMapFirstKey); 
-  newLineCheck(); 
-  ColumnAtMapFlowStart = Column; 
-  output("{ "); 
-} 
- 
-void Output::endFlowMapping() { 
-  StateStack.pop_back(); 
-  outputUpToEndOfLine(" }"); 
-} 
- 
-void Output::beginDocuments() { 
-  outputUpToEndOfLine("---"); 
-} 
- 
-bool Output::preflightDocument(unsigned index) { 
-  if (index > 0) 
-    outputUpToEndOfLine("\n---"); 
-  return true; 
-} 
- 
-void Output::postflightDocument() { 
-} 
- 
-void Output::endDocuments() { 
-  output("\n...\n"); 
-} 
- 
-unsigned Output::beginSequence() { 
-  StateStack.push_back(inSeqFirstElement); 
-  PaddingBeforeContainer = Padding; 
-  Padding = "\n"; 
-  return 0; 
-} 
- 
-void Output::endSequence() { 
-  // If we did not emit anything, we should explicitly emit an empty sequence 
-  if (StateStack.back() == inSeqFirstElement) { 
-    Padding = PaddingBeforeContainer; 
+bool Input::canElideEmptySequence() {
+  return false;
+}
+
+//===----------------------------------------------------------------------===//
+//  Output
+//===----------------------------------------------------------------------===//
+
+Output::Output(raw_ostream &yout, void *context, int WrapColumn)
+    : IO(context), Out(yout), WrapColumn(WrapColumn) {}
+
+Output::~Output() = default;
+
+bool Output::outputting() const {
+  return true;
+}
+
+void Output::beginMapping() {
+  StateStack.push_back(inMapFirstKey);
+  PaddingBeforeContainer = Padding;
+  Padding = "\n";
+}
+
+bool Output::mapTag(StringRef Tag, bool Use) {
+  if (Use) {
+    // If this tag is being written inside a sequence we should write the start
+    // of the sequence before writing the tag, otherwise the tag won't be
+    // attached to the element in the sequence, but rather the sequence itself.
+    bool SequenceElement = false;
+    if (StateStack.size() > 1) {
+      auto &E = StateStack[StateStack.size() - 2];
+      SequenceElement = inSeqAnyElement(E) || inFlowSeqAnyElement(E);
+    }
+    if (SequenceElement && StateStack.back() == inMapFirstKey) {
+      newLineCheck();
+    } else {
+      output(" ");
+    }
+    output(Tag);
+    if (SequenceElement) {
+      // If we're writing the tag during the first element of a map, the tag
+      // takes the place of the first element in the sequence.
+      if (StateStack.back() == inMapFirstKey) {
+        StateStack.pop_back();
+        StateStack.push_back(inMapOtherKey);
+      }
+      // Tags inside maps in sequences should act as keys in the map from a
+      // formatting perspective, so we always want a newline in a sequence.
+      Padding = "\n";
+    }
+  }
+  return Use;
+}
+
+void Output::endMapping() {
+  // If we did not map anything, we should explicitly emit an empty map
+  if (StateStack.back() == inMapFirstKey) {
+    Padding = PaddingBeforeContainer;
+    newLineCheck();
+    output("{}");
+    Padding = "\n";
+  }
+  StateStack.pop_back();
+}
+
+std::vector<StringRef> Output::keys() {
+  report_fatal_error("invalid call");
+}
+
+bool Output::preflightKey(const char *Key, bool Required, bool SameAsDefault,
+                          bool &UseDefault, void *&) {
+  UseDefault = false;
+  if (Required || !SameAsDefault || WriteDefaultValues) {
+    auto State = StateStack.back();
+    if (State == inFlowMapFirstKey || State == inFlowMapOtherKey) {
+      flowKey(Key);
+    } else {
+      newLineCheck();
+      paddedKey(Key);
+    }
+    return true;
+  }
+  return false;
+}
+
+void Output::postflightKey(void *) {
+  if (StateStack.back() == inMapFirstKey) {
+    StateStack.pop_back();
+    StateStack.push_back(inMapOtherKey);
+  } else if (StateStack.back() == inFlowMapFirstKey) {
+    StateStack.pop_back();
+    StateStack.push_back(inFlowMapOtherKey);
+  }
+}
+
+void Output::beginFlowMapping() {
+  StateStack.push_back(inFlowMapFirstKey);
+  newLineCheck();
+  ColumnAtMapFlowStart = Column;
+  output("{ ");
+}
+
+void Output::endFlowMapping() {
+  StateStack.pop_back();
+  outputUpToEndOfLine(" }");
+}
+
+void Output::beginDocuments() {
+  outputUpToEndOfLine("---");
+}
+
+bool Output::preflightDocument(unsigned index) {
+  if (index > 0)
+    outputUpToEndOfLine("\n---");
+  return true;
+}
+
+void Output::postflightDocument() {
+}
+
+void Output::endDocuments() {
+  output("\n...\n");
+}
+
+unsigned Output::beginSequence() {
+  StateStack.push_back(inSeqFirstElement);
+  PaddingBeforeContainer = Padding;
+  Padding = "\n";
+  return 0;
+}
+
+void Output::endSequence() {
+  // If we did not emit anything, we should explicitly emit an empty sequence
+  if (StateStack.back() == inSeqFirstElement) {
+    Padding = PaddingBeforeContainer;
     newLineCheck(/*EmptySequence=*/true);
-    output("[]"); 
-    Padding = "\n"; 
-  } 
-  StateStack.pop_back(); 
-} 
- 
-bool Output::preflightElement(unsigned, void *&) { 
-  return true; 
-} 
- 
-void Output::postflightElement(void *) { 
-  if (StateStack.back() == inSeqFirstElement) { 
-    StateStack.pop_back(); 
-    StateStack.push_back(inSeqOtherElement); 
-  } else if (StateStack.back() == inFlowSeqFirstElement) { 
-    StateStack.pop_back(); 
-    StateStack.push_back(inFlowSeqOtherElement); 
-  } 
-} 
- 
-unsigned Output::beginFlowSequence() { 
-  StateStack.push_back(inFlowSeqFirstElement); 
-  newLineCheck(); 
-  ColumnAtFlowStart = Column; 
-  output("[ "); 
-  NeedFlowSequenceComma = false; 
-  return 0; 
-} 
- 
-void Output::endFlowSequence() { 
-  StateStack.pop_back(); 
-  outputUpToEndOfLine(" ]"); 
-} 
- 
-bool Output::preflightFlowElement(unsigned, void *&) { 
-  if (NeedFlowSequenceComma) 
-    output(", "); 
-  if (WrapColumn && Column > WrapColumn) { 
-    output("\n"); 
-    for (int i = 0; i < ColumnAtFlowStart; ++i) 
-      output(" "); 
-    Column = ColumnAtFlowStart; 
-    output("  "); 
-  } 
-  return true; 
-} 
- 
-void Output::postflightFlowElement(void *) { 
-  NeedFlowSequenceComma = true; 
-} 
- 
-void Output::beginEnumScalar() { 
-  EnumerationMatchFound = false; 
-} 
- 
-bool Output::matchEnumScalar(const char *Str, bool Match) { 
-  if (Match && !EnumerationMatchFound) { 
-    newLineCheck(); 
-    outputUpToEndOfLine(Str); 
-    EnumerationMatchFound = true; 
-  } 
-  return false; 
-} 
- 
-bool Output::matchEnumFallback() { 
-  if (EnumerationMatchFound) 
-    return false; 
-  EnumerationMatchFound = true; 
-  return true; 
-} 
- 
-void Output::endEnumScalar() { 
-  if (!EnumerationMatchFound) 
-    llvm_unreachable("bad runtime enum value"); 
-} 
- 
-bool Output::beginBitSetScalar(bool &DoClear) { 
-  newLineCheck(); 
-  output("[ "); 
-  NeedBitValueComma = false; 
-  DoClear = false; 
-  return true; 
-} 
- 
-bool Output::bitSetMatch(const char *Str, bool Matches) { 
-  if (Matches) { 
-    if (NeedBitValueComma) 
-      output(", "); 
-    output(Str); 
-    NeedBitValueComma = true; 
-  } 
-  return false; 
-} 
- 
-void Output::endBitSetScalar() { 
-  outputUpToEndOfLine(" ]"); 
-} 
- 
-void Output::scalarString(StringRef &S, QuotingType MustQuote) { 
-  newLineCheck(); 
-  if (S.empty()) { 
-    // Print '' for the empty string because leaving the field empty is not 
-    // allowed. 
-    outputUpToEndOfLine("''"); 
-    return; 
-  } 
-  if (MustQuote == QuotingType::None) { 
-    // Only quote if we must. 
-    outputUpToEndOfLine(S); 
-    return; 
-  } 
- 
-  const char *const Quote = MustQuote == QuotingType::Single ? "'" : "\""; 
-  output(Quote); // Starting quote. 
- 
-  // When using double-quoted strings (and only in that case), non-printable characters may be 
-  // present, and will be escaped using a variety of unicode-scalar and special short-form 
-  // escapes. This is handled in yaml::escape. 
-  if (MustQuote == QuotingType::Double) { 
-    output(yaml::escape(S, /* EscapePrintable= */ false)); 
-    outputUpToEndOfLine(Quote); 
-    return; 
-  } 
- 
-  unsigned i = 0; 
-  unsigned j = 0; 
-  unsigned End = S.size(); 
-  const char *Base = S.data(); 
- 
-  // When using single-quoted strings, any single quote ' must be doubled to be escaped. 
-  while (j < End) { 
-    if (S[j] == '\'') {                    // Escape quotes. 
-      output(StringRef(&Base[i], j - i));  // "flush". 
-      output(StringLiteral("''"));         // Print it as '' 
-      i = j + 1; 
-    } 
-    ++j; 
-  } 
-  output(StringRef(&Base[i], j - i)); 
-  outputUpToEndOfLine(Quote); // Ending quote. 
-} 
- 
-void Output::blockScalarString(StringRef &S) { 
-  if (!StateStack.empty()) 
-    newLineCheck(); 
-  output(" |"); 
-  outputNewLine(); 
- 
-  unsigned Indent = StateStack.empty() ? 1 : StateStack.size(); 
- 
-  auto Buffer = MemoryBuffer::getMemBuffer(S, "", false); 
-  for (line_iterator Lines(*Buffer, false); !Lines.is_at_end(); ++Lines) { 
-    for (unsigned I = 0; I < Indent; ++I) { 
-      output("  "); 
-    } 
-    output(*Lines); 
-    outputNewLine(); 
-  } 
-} 
- 
-void Output::scalarTag(std::string &Tag) { 
-  if (Tag.empty()) 
-    return; 
-  newLineCheck(); 
-  output(Tag); 
-  output(" "); 
-} 
- 
-void Output::setError(const Twine &message) { 
-} 
- 
-bool Output::canElideEmptySequence() { 
-  // Normally, with an optional key/value where the value is an empty sequence, 
-  // the whole key/value can be not written.  But, that produces wrong yaml 
-  // if the key/value is the only thing in the map and the map is used in 
-  // a sequence.  This detects if the this sequence is the first key/value 
-  // in map that itself is embedded in a sequence. 
-  if (StateStack.size() < 2) 
-    return true; 
-  if (StateStack.back() != inMapFirstKey) 
-    return true; 
-  return !inSeqAnyElement(StateStack[StateStack.size() - 2]); 
-} 
- 
-void Output::output(StringRef s) { 
-  Column += s.size(); 
-  Out << s; 
-} 
- 
-void Output::outputUpToEndOfLine(StringRef s) { 
-  output(s); 
-  if (StateStack.empty() || (!inFlowSeqAnyElement(StateStack.back()) && 
-                             !inFlowMapAnyKey(StateStack.back()))) 
-    Padding = "\n"; 
-} 
- 
-void Output::outputNewLine() { 
-  Out << "\n"; 
-  Column = 0; 
-} 
- 
-// if seq at top, indent as if map, then add "- " 
-// if seq in middle, use "- " if firstKey, else use "  " 
-// 
- 
+    output("[]");
+    Padding = "\n";
+  }
+  StateStack.pop_back();
+}
+
+bool Output::preflightElement(unsigned, void *&) {
+  return true;
+}
+
+void Output::postflightElement(void *) {
+  if (StateStack.back() == inSeqFirstElement) {
+    StateStack.pop_back();
+    StateStack.push_back(inSeqOtherElement);
+  } else if (StateStack.back() == inFlowSeqFirstElement) {
+    StateStack.pop_back();
+    StateStack.push_back(inFlowSeqOtherElement);
+  }
+}
+
+unsigned Output::beginFlowSequence() {
+  StateStack.push_back(inFlowSeqFirstElement);
+  newLineCheck();
+  ColumnAtFlowStart = Column;
+  output("[ ");
+  NeedFlowSequenceComma = false;
+  return 0;
+}
+
+void Output::endFlowSequence() {
+  StateStack.pop_back();
+  outputUpToEndOfLine(" ]");
+}
+
+bool Output::preflightFlowElement(unsigned, void *&) {
+  if (NeedFlowSequenceComma)
+    output(", ");
+  if (WrapColumn && Column > WrapColumn) {
+    output("\n");
+    for (int i = 0; i < ColumnAtFlowStart; ++i)
+      output(" ");
+    Column = ColumnAtFlowStart;
+    output("  ");
+  }
+  return true;
+}
+
+void Output::postflightFlowElement(void *) {
+  NeedFlowSequenceComma = true;
+}
+
+void Output::beginEnumScalar() {
+  EnumerationMatchFound = false;
+}
+
+bool Output::matchEnumScalar(const char *Str, bool Match) {
+  if (Match && !EnumerationMatchFound) {
+    newLineCheck();
+    outputUpToEndOfLine(Str);
+    EnumerationMatchFound = true;
+  }
+  return false;
+}
+
+bool Output::matchEnumFallback() {
+  if (EnumerationMatchFound)
+    return false;
+  EnumerationMatchFound = true;
+  return true;
+}
+
+void Output::endEnumScalar() {
+  if (!EnumerationMatchFound)
+    llvm_unreachable("bad runtime enum value");
+}
+
+bool Output::beginBitSetScalar(bool &DoClear) {
+  newLineCheck();
+  output("[ ");
+  NeedBitValueComma = false;
+  DoClear = false;
+  return true;
+}
+
+bool Output::bitSetMatch(const char *Str, bool Matches) {
+  if (Matches) {
+    if (NeedBitValueComma)
+      output(", ");
+    output(Str);
+    NeedBitValueComma = true;
+  }
+  return false;
+}
+
+void Output::endBitSetScalar() {
+  outputUpToEndOfLine(" ]");
+}
+
+void Output::scalarString(StringRef &S, QuotingType MustQuote) {
+  newLineCheck();
+  if (S.empty()) {
+    // Print '' for the empty string because leaving the field empty is not
+    // allowed.
+    outputUpToEndOfLine("''");
+    return;
+  }
+  if (MustQuote == QuotingType::None) {
+    // Only quote if we must.
+    outputUpToEndOfLine(S);
+    return;
+  }
+
+  const char *const Quote = MustQuote == QuotingType::Single ? "'" : "\"";
+  output(Quote); // Starting quote.
+
+  // When using double-quoted strings (and only in that case), non-printable characters may be
+  // present, and will be escaped using a variety of unicode-scalar and special short-form
+  // escapes. This is handled in yaml::escape.
+  if (MustQuote == QuotingType::Double) {
+    output(yaml::escape(S, /* EscapePrintable= */ false));
+    outputUpToEndOfLine(Quote);
+    return;
+  }
+
+  unsigned i = 0;
+  unsigned j = 0;
+  unsigned End = S.size();
+  const char *Base = S.data();
+
+  // When using single-quoted strings, any single quote ' must be doubled to be escaped.
+  while (j < End) {
+    if (S[j] == '\'') {                    // Escape quotes.
+      output(StringRef(&Base[i], j - i));  // "flush".
+      output(StringLiteral("''"));         // Print it as ''
+      i = j + 1;
+    }
+    ++j;
+  }
+  output(StringRef(&Base[i], j - i));
+  outputUpToEndOfLine(Quote); // Ending quote.
+}
+
+void Output::blockScalarString(StringRef &S) {
+  if (!StateStack.empty())
+    newLineCheck();
+  output(" |");
+  outputNewLine();
+
+  unsigned Indent = StateStack.empty() ? 1 : StateStack.size();
+
+  auto Buffer = MemoryBuffer::getMemBuffer(S, "", false);
+  for (line_iterator Lines(*Buffer, false); !Lines.is_at_end(); ++Lines) {
+    for (unsigned I = 0; I < Indent; ++I) {
+      output("  ");
+    }
+    output(*Lines);
+    outputNewLine();
+  }
+}
+
+void Output::scalarTag(std::string &Tag) {
+  if (Tag.empty())
+    return;
+  newLineCheck();
+  output(Tag);
+  output(" ");
+}
+
+void Output::setError(const Twine &message) {
+}
+
+bool Output::canElideEmptySequence() {
+  // Normally, with an optional key/value where the value is an empty sequence,
+  // the whole key/value can be not written.  But, that produces wrong yaml
+  // if the key/value is the only thing in the map and the map is used in
+  // a sequence.  This detects if the this sequence is the first key/value
+  // in map that itself is embedded in a sequence.
+  if (StateStack.size() < 2)
+    return true;
+  if (StateStack.back() != inMapFirstKey)
+    return true;
+  return !inSeqAnyElement(StateStack[StateStack.size() - 2]);
+}
+
+void Output::output(StringRef s) {
+  Column += s.size();
+  Out << s;
+}
+
+void Output::outputUpToEndOfLine(StringRef s) {
+  output(s);
+  if (StateStack.empty() || (!inFlowSeqAnyElement(StateStack.back()) &&
+                             !inFlowMapAnyKey(StateStack.back())))
+    Padding = "\n";
+}
+
+void Output::outputNewLine() {
+  Out << "\n";
+  Column = 0;
+}
+
+// if seq at top, indent as if map, then add "- "
+// if seq in middle, use "- " if firstKey, else use "  "
+//
+
 void Output::newLineCheck(bool EmptySequence) {
-  if (Padding != "\n") { 
-    output(Padding); 
-    Padding = {}; 
-    return; 
-  } 
-  outputNewLine(); 
-  Padding = {}; 
- 
+  if (Padding != "\n") {
+    output(Padding);
+    Padding = {};
+    return;
+  }
+  outputNewLine();
+  Padding = {};
+
   if (StateStack.size() == 0 || EmptySequence)
-    return; 
- 
-  unsigned Indent = StateStack.size() - 1; 
-  bool OutputDash = false; 
- 
-  if (StateStack.back() == inSeqFirstElement || 
-      StateStack.back() == inSeqOtherElement) { 
-    OutputDash = true; 
-  } else if ((StateStack.size() > 1) && 
-             ((StateStack.back() == inMapFirstKey) || 
-              inFlowSeqAnyElement(StateStack.back()) || 
-              (StateStack.back() == inFlowMapFirstKey)) && 
-             inSeqAnyElement(StateStack[StateStack.size() - 2])) { 
-    --Indent; 
-    OutputDash = true; 
-  } 
- 
-  for (unsigned i = 0; i < Indent; ++i) { 
-    output("  "); 
-  } 
-  if (OutputDash) { 
-    output("- "); 
-  } 
-} 
- 
-void Output::paddedKey(StringRef key) { 
-  output(key); 
-  output(":"); 
-  const char *spaces = "                "; 
-  if (key.size() < strlen(spaces)) 
-    Padding = &spaces[key.size()]; 
-  else 
-    Padding = " "; 
-} 
- 
-void Output::flowKey(StringRef Key) { 
-  if (StateStack.back() == inFlowMapOtherKey) 
-    output(", "); 
-  if (WrapColumn && Column > WrapColumn) { 
-    output("\n"); 
-    for (int I = 0; I < ColumnAtMapFlowStart; ++I) 
-      output(" "); 
-    Column = ColumnAtMapFlowStart; 
-    output("  "); 
-  } 
-  output(Key); 
-  output(": "); 
-} 
- 
-NodeKind Output::getNodeKind() { report_fatal_error("invalid call"); } 
- 
-bool Output::inSeqAnyElement(InState State) { 
-  return State == inSeqFirstElement || State == inSeqOtherElement; 
-} 
- 
-bool Output::inFlowSeqAnyElement(InState State) { 
-  return State == inFlowSeqFirstElement || State == inFlowSeqOtherElement; 
-} 
- 
-bool Output::inMapAnyKey(InState State) { 
-  return State == inMapFirstKey || State == inMapOtherKey; 
-} 
- 
-bool Output::inFlowMapAnyKey(InState State) { 
-  return State == inFlowMapFirstKey || State == inFlowMapOtherKey; 
-} 
- 
-//===----------------------------------------------------------------------===// 
-//  traits for built-in types 
-//===----------------------------------------------------------------------===// 
- 
-void ScalarTraits<bool>::output(const bool &Val, void *, raw_ostream &Out) { 
-  Out << (Val ? "true" : "false"); 
-} 
- 
-StringRef ScalarTraits<bool>::input(StringRef Scalar, void *, bool &Val) { 
+    return;
+
+  unsigned Indent = StateStack.size() - 1;
+  bool OutputDash = false;
+
+  if (StateStack.back() == inSeqFirstElement ||
+      StateStack.back() == inSeqOtherElement) {
+    OutputDash = true;
+  } else if ((StateStack.size() > 1) &&
+             ((StateStack.back() == inMapFirstKey) ||
+              inFlowSeqAnyElement(StateStack.back()) ||
+              (StateStack.back() == inFlowMapFirstKey)) &&
+             inSeqAnyElement(StateStack[StateStack.size() - 2])) {
+    --Indent;
+    OutputDash = true;
+  }
+
+  for (unsigned i = 0; i < Indent; ++i) {
+    output("  ");
+  }
+  if (OutputDash) {
+    output("- ");
+  }
+}
+
+void Output::paddedKey(StringRef key) {
+  output(key);
+  output(":");
+  const char *spaces = "                ";
+  if (key.size() < strlen(spaces))
+    Padding = &spaces[key.size()];
+  else
+    Padding = " ";
+}
+
+void Output::flowKey(StringRef Key) {
+  if (StateStack.back() == inFlowMapOtherKey)
+    output(", ");
+  if (WrapColumn && Column > WrapColumn) {
+    output("\n");
+    for (int I = 0; I < ColumnAtMapFlowStart; ++I)
+      output(" ");
+    Column = ColumnAtMapFlowStart;
+    output("  ");
+  }
+  output(Key);
+  output(": ");
+}
+
+NodeKind Output::getNodeKind() { report_fatal_error("invalid call"); }
+
+bool Output::inSeqAnyElement(InState State) {
+  return State == inSeqFirstElement || State == inSeqOtherElement;
+}
+
+bool Output::inFlowSeqAnyElement(InState State) {
+  return State == inFlowSeqFirstElement || State == inFlowSeqOtherElement;
+}
+
+bool Output::inMapAnyKey(InState State) {
+  return State == inMapFirstKey || State == inMapOtherKey;
+}
+
+bool Output::inFlowMapAnyKey(InState State) {
+  return State == inFlowMapFirstKey || State == inFlowMapOtherKey;
+}
+
+//===----------------------------------------------------------------------===//
+//  traits for built-in types
+//===----------------------------------------------------------------------===//
+
+void ScalarTraits<bool>::output(const bool &Val, void *, raw_ostream &Out) {
+  Out << (Val ? "true" : "false");
+}
+
+StringRef ScalarTraits<bool>::input(StringRef Scalar, void *, bool &Val) {
   if (llvm::Optional<bool> Parsed = parseBool(Scalar)) {
     Val = *Parsed;
-    return StringRef(); 
-  } 
-  return "invalid boolean"; 
-} 
- 
-void ScalarTraits<StringRef>::output(const StringRef &Val, void *, 
-                                     raw_ostream &Out) { 
-  Out << Val; 
-} 
- 
-StringRef ScalarTraits<StringRef>::input(StringRef Scalar, void *, 
-                                         StringRef &Val) { 
-  Val = Scalar; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<std::string>::output(const std::string &Val, void *, 
-                                       raw_ostream &Out) { 
-  Out << Val; 
-} 
- 
-StringRef ScalarTraits<std::string>::input(StringRef Scalar, void *, 
-                                           std::string &Val) { 
-  Val = Scalar.str(); 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<uint8_t>::output(const uint8_t &Val, void *, 
-                                   raw_ostream &Out) { 
-  // use temp uin32_t because ostream thinks uint8_t is a character 
-  uint32_t Num = Val; 
-  Out << Num; 
-} 
- 
-StringRef ScalarTraits<uint8_t>::input(StringRef Scalar, void *, uint8_t &Val) { 
-  unsigned long long n; 
-  if (getAsUnsignedInteger(Scalar, 0, n)) 
-    return "invalid number"; 
-  if (n > 0xFF) 
-    return "out of range number"; 
-  Val = n; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<uint16_t>::output(const uint16_t &Val, void *, 
-                                    raw_ostream &Out) { 
-  Out << Val; 
-} 
- 
-StringRef ScalarTraits<uint16_t>::input(StringRef Scalar, void *, 
-                                        uint16_t &Val) { 
-  unsigned long long n; 
-  if (getAsUnsignedInteger(Scalar, 0, n)) 
-    return "invalid number"; 
-  if (n > 0xFFFF) 
-    return "out of range number"; 
-  Val = n; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<uint32_t>::output(const uint32_t &Val, void *, 
-                                    raw_ostream &Out) { 
-  Out << Val; 
-} 
- 
-StringRef ScalarTraits<uint32_t>::input(StringRef Scalar, void *, 
-                                        uint32_t &Val) { 
-  unsigned long long n; 
-  if (getAsUnsignedInteger(Scalar, 0, n)) 
-    return "invalid number"; 
-  if (n > 0xFFFFFFFFUL) 
-    return "out of range number"; 
-  Val = n; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<uint64_t>::output(const uint64_t &Val, void *, 
-                                    raw_ostream &Out) { 
-  Out << Val; 
-} 
- 
-StringRef ScalarTraits<uint64_t>::input(StringRef Scalar, void *, 
-                                        uint64_t &Val) { 
-  unsigned long long N; 
-  if (getAsUnsignedInteger(Scalar, 0, N)) 
-    return "invalid number"; 
-  Val = N; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<int8_t>::output(const int8_t &Val, void *, raw_ostream &Out) { 
-  // use temp in32_t because ostream thinks int8_t is a character 
-  int32_t Num = Val; 
-  Out << Num; 
-} 
- 
-StringRef ScalarTraits<int8_t>::input(StringRef Scalar, void *, int8_t &Val) { 
-  long long N; 
-  if (getAsSignedInteger(Scalar, 0, N)) 
-    return "invalid number"; 
-  if ((N > 127) || (N < -128)) 
-    return "out of range number"; 
-  Val = N; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<int16_t>::output(const int16_t &Val, void *, 
-                                   raw_ostream &Out) { 
-  Out << Val; 
-} 
- 
-StringRef ScalarTraits<int16_t>::input(StringRef Scalar, void *, int16_t &Val) { 
-  long long N; 
-  if (getAsSignedInteger(Scalar, 0, N)) 
-    return "invalid number"; 
-  if ((N > INT16_MAX) || (N < INT16_MIN)) 
-    return "out of range number"; 
-  Val = N; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<int32_t>::output(const int32_t &Val, void *, 
-                                   raw_ostream &Out) { 
-  Out << Val; 
-} 
- 
-StringRef ScalarTraits<int32_t>::input(StringRef Scalar, void *, int32_t &Val) { 
-  long long N; 
-  if (getAsSignedInteger(Scalar, 0, N)) 
-    return "invalid number"; 
-  if ((N > INT32_MAX) || (N < INT32_MIN)) 
-    return "out of range number"; 
-  Val = N; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<int64_t>::output(const int64_t &Val, void *, 
-                                   raw_ostream &Out) { 
-  Out << Val; 
-} 
- 
-StringRef ScalarTraits<int64_t>::input(StringRef Scalar, void *, int64_t &Val) { 
-  long long N; 
-  if (getAsSignedInteger(Scalar, 0, N)) 
-    return "invalid number"; 
-  Val = N; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<double>::output(const double &Val, void *, raw_ostream &Out) { 
-  Out << format("%g", Val); 
-} 
- 
-StringRef ScalarTraits<double>::input(StringRef Scalar, void *, double &Val) { 
-  if (to_float(Scalar, Val)) 
-    return StringRef(); 
-  return "invalid floating point number"; 
-} 
- 
-void ScalarTraits<float>::output(const float &Val, void *, raw_ostream &Out) { 
-  Out << format("%g", Val); 
-} 
- 
-StringRef ScalarTraits<float>::input(StringRef Scalar, void *, float &Val) { 
-  if (to_float(Scalar, Val)) 
-    return StringRef(); 
-  return "invalid floating point number"; 
-} 
- 
-void ScalarTraits<Hex8>::output(const Hex8 &Val, void *, raw_ostream &Out) { 
+    return StringRef();
+  }
+  return "invalid boolean";
+}
+
+void ScalarTraits<StringRef>::output(const StringRef &Val, void *,
+                                     raw_ostream &Out) {
+  Out << Val;
+}
+
+StringRef ScalarTraits<StringRef>::input(StringRef Scalar, void *,
+                                         StringRef &Val) {
+  Val = Scalar;
+  return StringRef();
+}
+
+void ScalarTraits<std::string>::output(const std::string &Val, void *,
+                                       raw_ostream &Out) {
+  Out << Val;
+}
+
+StringRef ScalarTraits<std::string>::input(StringRef Scalar, void *,
+                                           std::string &Val) {
+  Val = Scalar.str();
+  return StringRef();
+}
+
+void ScalarTraits<uint8_t>::output(const uint8_t &Val, void *,
+                                   raw_ostream &Out) {
+  // use temp uin32_t because ostream thinks uint8_t is a character
+  uint32_t Num = Val;
+  Out << Num;
+}
+
+StringRef ScalarTraits<uint8_t>::input(StringRef Scalar, void *, uint8_t &Val) {
+  unsigned long long n;
+  if (getAsUnsignedInteger(Scalar, 0, n))
+    return "invalid number";
+  if (n > 0xFF)
+    return "out of range number";
+  Val = n;
+  return StringRef();
+}
+
+void ScalarTraits<uint16_t>::output(const uint16_t &Val, void *,
+                                    raw_ostream &Out) {
+  Out << Val;
+}
+
+StringRef ScalarTraits<uint16_t>::input(StringRef Scalar, void *,
+                                        uint16_t &Val) {
+  unsigned long long n;
+  if (getAsUnsignedInteger(Scalar, 0, n))
+    return "invalid number";
+  if (n > 0xFFFF)
+    return "out of range number";
+  Val = n;
+  return StringRef();
+}
+
+void ScalarTraits<uint32_t>::output(const uint32_t &Val, void *,
+                                    raw_ostream &Out) {
+  Out << Val;
+}
+
+StringRef ScalarTraits<uint32_t>::input(StringRef Scalar, void *,
+                                        uint32_t &Val) {
+  unsigned long long n;
+  if (getAsUnsignedInteger(Scalar, 0, n))
+    return "invalid number";
+  if (n > 0xFFFFFFFFUL)
+    return "out of range number";
+  Val = n;
+  return StringRef();
+}
+
+void ScalarTraits<uint64_t>::output(const uint64_t &Val, void *,
+                                    raw_ostream &Out) {
+  Out << Val;
+}
+
+StringRef ScalarTraits<uint64_t>::input(StringRef Scalar, void *,
+                                        uint64_t &Val) {
+  unsigned long long N;
+  if (getAsUnsignedInteger(Scalar, 0, N))
+    return "invalid number";
+  Val = N;
+  return StringRef();
+}
+
+void ScalarTraits<int8_t>::output(const int8_t &Val, void *, raw_ostream &Out) {
+  // use temp in32_t because ostream thinks int8_t is a character
+  int32_t Num = Val;
+  Out << Num;
+}
+
+StringRef ScalarTraits<int8_t>::input(StringRef Scalar, void *, int8_t &Val) {
+  long long N;
+  if (getAsSignedInteger(Scalar, 0, N))
+    return "invalid number";
+  if ((N > 127) || (N < -128))
+    return "out of range number";
+  Val = N;
+  return StringRef();
+}
+
+void ScalarTraits<int16_t>::output(const int16_t &Val, void *,
+                                   raw_ostream &Out) {
+  Out << Val;
+}
+
+StringRef ScalarTraits<int16_t>::input(StringRef Scalar, void *, int16_t &Val) {
+  long long N;
+  if (getAsSignedInteger(Scalar, 0, N))
+    return "invalid number";
+  if ((N > INT16_MAX) || (N < INT16_MIN))
+    return "out of range number";
+  Val = N;
+  return StringRef();
+}
+
+void ScalarTraits<int32_t>::output(const int32_t &Val, void *,
+                                   raw_ostream &Out) {
+  Out << Val;
+}
+
+StringRef ScalarTraits<int32_t>::input(StringRef Scalar, void *, int32_t &Val) {
+  long long N;
+  if (getAsSignedInteger(Scalar, 0, N))
+    return "invalid number";
+  if ((N > INT32_MAX) || (N < INT32_MIN))
+    return "out of range number";
+  Val = N;
+  return StringRef();
+}
+
+void ScalarTraits<int64_t>::output(const int64_t &Val, void *,
+                                   raw_ostream &Out) {
+  Out << Val;
+}
+
+StringRef ScalarTraits<int64_t>::input(StringRef Scalar, void *, int64_t &Val) {
+  long long N;
+  if (getAsSignedInteger(Scalar, 0, N))
+    return "invalid number";
+  Val = N;
+  return StringRef();
+}
+
+void ScalarTraits<double>::output(const double &Val, void *, raw_ostream &Out) {
+  Out << format("%g", Val);
+}
+
+StringRef ScalarTraits<double>::input(StringRef Scalar, void *, double &Val) {
+  if (to_float(Scalar, Val))
+    return StringRef();
+  return "invalid floating point number";
+}
+
+void ScalarTraits<float>::output(const float &Val, void *, raw_ostream &Out) {
+  Out << format("%g", Val);
+}
+
+StringRef ScalarTraits<float>::input(StringRef Scalar, void *, float &Val) {
+  if (to_float(Scalar, Val))
+    return StringRef();
+  return "invalid floating point number";
+}
+
+void ScalarTraits<Hex8>::output(const Hex8 &Val, void *, raw_ostream &Out) {
   Out << format("0x%" PRIX8, (uint8_t)Val);
-} 
- 
-StringRef ScalarTraits<Hex8>::input(StringRef Scalar, void *, Hex8 &Val) { 
-  unsigned long long n; 
-  if (getAsUnsignedInteger(Scalar, 0, n)) 
-    return "invalid hex8 number"; 
-  if (n > 0xFF) 
-    return "out of range hex8 number"; 
-  Val = n; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<Hex16>::output(const Hex16 &Val, void *, raw_ostream &Out) { 
+}
+
+StringRef ScalarTraits<Hex8>::input(StringRef Scalar, void *, Hex8 &Val) {
+  unsigned long long n;
+  if (getAsUnsignedInteger(Scalar, 0, n))
+    return "invalid hex8 number";
+  if (n > 0xFF)
+    return "out of range hex8 number";
+  Val = n;
+  return StringRef();
+}
+
+void ScalarTraits<Hex16>::output(const Hex16 &Val, void *, raw_ostream &Out) {
   Out << format("0x%" PRIX16, (uint16_t)Val);
-} 
- 
-StringRef ScalarTraits<Hex16>::input(StringRef Scalar, void *, Hex16 &Val) { 
-  unsigned long long n; 
-  if (getAsUnsignedInteger(Scalar, 0, n)) 
-    return "invalid hex16 number"; 
-  if (n > 0xFFFF) 
-    return "out of range hex16 number"; 
-  Val = n; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<Hex32>::output(const Hex32 &Val, void *, raw_ostream &Out) { 
+}
+
+StringRef ScalarTraits<Hex16>::input(StringRef Scalar, void *, Hex16 &Val) {
+  unsigned long long n;
+  if (getAsUnsignedInteger(Scalar, 0, n))
+    return "invalid hex16 number";
+  if (n > 0xFFFF)
+    return "out of range hex16 number";
+  Val = n;
+  return StringRef();
+}
+
+void ScalarTraits<Hex32>::output(const Hex32 &Val, void *, raw_ostream &Out) {
   Out << format("0x%" PRIX32, (uint32_t)Val);
-} 
- 
-StringRef ScalarTraits<Hex32>::input(StringRef Scalar, void *, Hex32 &Val) { 
-  unsigned long long n; 
-  if (getAsUnsignedInteger(Scalar, 0, n)) 
-    return "invalid hex32 number"; 
-  if (n > 0xFFFFFFFFUL) 
-    return "out of range hex32 number"; 
-  Val = n; 
-  return StringRef(); 
-} 
- 
-void ScalarTraits<Hex64>::output(const Hex64 &Val, void *, raw_ostream &Out) { 
+}
+
+StringRef ScalarTraits<Hex32>::input(StringRef Scalar, void *, Hex32 &Val) {
+  unsigned long long n;
+  if (getAsUnsignedInteger(Scalar, 0, n))
+    return "invalid hex32 number";
+  if (n > 0xFFFFFFFFUL)
+    return "out of range hex32 number";
+  Val = n;
+  return StringRef();
+}
+
+void ScalarTraits<Hex64>::output(const Hex64 &Val, void *, raw_ostream &Out) {
   Out << format("0x%" PRIX64, (uint64_t)Val);
-} 
- 
-StringRef ScalarTraits<Hex64>::input(StringRef Scalar, void *, Hex64 &Val) { 
-  unsigned long long Num; 
-  if (getAsUnsignedInteger(Scalar, 0, Num)) 
-    return "invalid hex64 number"; 
-  Val = Num; 
-  return StringRef(); 
-} 
+}
+
+StringRef ScalarTraits<Hex64>::input(StringRef Scalar, void *, Hex64 &Val) {
+  unsigned long long Num;
+  if (getAsUnsignedInteger(Scalar, 0, Num))
+    return "invalid hex64 number";
+  Val = Num;
+  return StringRef();
+}
 
 void ScalarTraits<VersionTuple>::output(const VersionTuple &Val, void *,
                                         llvm::raw_ostream &Out) {