xref: /freebsd/contrib/llvm-project/llvm/lib/Support/YAMLTraits.cpp (revision e6bfd18d21b225af6a0ed67ceeaf1293b7b9eba5)
1 //===- lib/Support/YAMLTraits.cpp -----------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/Support/YAMLTraits.h"
10 #include "llvm/ADT/STLExtras.h"
11 #include "llvm/ADT/SmallString.h"
12 #include "llvm/ADT/StringExtras.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/ADT/Twine.h"
15 #include "llvm/Support/Casting.h"
16 #include "llvm/Support/Errc.h"
17 #include "llvm/Support/ErrorHandling.h"
18 #include "llvm/Support/Format.h"
19 #include "llvm/Support/LineIterator.h"
20 #include "llvm/Support/MemoryBuffer.h"
21 #include "llvm/Support/VersionTuple.h"
22 #include "llvm/Support/YAMLParser.h"
23 #include "llvm/Support/raw_ostream.h"
24 #include <algorithm>
25 #include <cassert>
26 #include <cstdint>
27 #include <cstring>
28 #include <string>
29 #include <vector>
30 
31 using namespace llvm;
32 using namespace yaml;
33 
34 //===----------------------------------------------------------------------===//
35 //  IO
36 //===----------------------------------------------------------------------===//
37 
38 IO::IO(void *Context) : Ctxt(Context) {}
39 
40 IO::~IO() = default;
41 
42 void *IO::getContext() const {
43   return Ctxt;
44 }
45 
46 void IO::setContext(void *Context) {
47   Ctxt = Context;
48 }
49 
50 void IO::setAllowUnknownKeys(bool Allow) {
51   llvm_unreachable("Only supported for Input");
52 }
53 
54 //===----------------------------------------------------------------------===//
55 //  Input
56 //===----------------------------------------------------------------------===//
57 
58 Input::Input(StringRef InputContent, void *Ctxt,
59              SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt)
60     : IO(Ctxt), Strm(new Stream(InputContent, SrcMgr, false, &EC)) {
61   if (DiagHandler)
62     SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt);
63   DocIterator = Strm->begin();
64 }
65 
66 Input::Input(MemoryBufferRef Input, void *Ctxt,
67              SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt)
68     : IO(Ctxt), Strm(new Stream(Input, SrcMgr, false, &EC)) {
69   if (DiagHandler)
70     SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt);
71   DocIterator = Strm->begin();
72 }
73 
74 Input::~Input() = default;
75 
76 std::error_code Input::error() { return EC; }
77 
78 // Pin the vtables to this file.
79 void Input::HNode::anchor() {}
80 void Input::EmptyHNode::anchor() {}
81 void Input::ScalarHNode::anchor() {}
82 void Input::MapHNode::anchor() {}
83 void Input::SequenceHNode::anchor() {}
84 
85 bool Input::outputting() const {
86   return false;
87 }
88 
89 bool Input::setCurrentDocument() {
90   if (DocIterator != Strm->end()) {
91     Node *N = DocIterator->getRoot();
92     if (!N) {
93       EC = make_error_code(errc::invalid_argument);
94       return false;
95     }
96 
97     if (isa<NullNode>(N)) {
98       // Empty files are allowed and ignored
99       ++DocIterator;
100       return setCurrentDocument();
101     }
102     TopNode = createHNodes(N);
103     CurrentNode = TopNode.get();
104     return true;
105   }
106   return false;
107 }
108 
109 bool Input::nextDocument() {
110   return ++DocIterator != Strm->end();
111 }
112 
113 const Node *Input::getCurrentNode() const {
114   return CurrentNode ? CurrentNode->_node : nullptr;
115 }
116 
117 bool Input::mapTag(StringRef Tag, bool Default) {
118   // CurrentNode can be null if setCurrentDocument() was unable to
119   // parse the document because it was invalid or empty.
120   if (!CurrentNode)
121     return false;
122 
123   std::string foundTag = CurrentNode->_node->getVerbatimTag();
124   if (foundTag.empty()) {
125     // If no tag found and 'Tag' is the default, say it was found.
126     return Default;
127   }
128   // Return true iff found tag matches supplied tag.
129   return Tag.equals(foundTag);
130 }
131 
132 void Input::beginMapping() {
133   if (EC)
134     return;
135   // CurrentNode can be null if the document is empty.
136   MapHNode *MN = dyn_cast_or_null<MapHNode>(CurrentNode);
137   if (MN) {
138     MN->ValidKeys.clear();
139   }
140 }
141 
142 std::vector<StringRef> Input::keys() {
143   MapHNode *MN = dyn_cast<MapHNode>(CurrentNode);
144   std::vector<StringRef> Ret;
145   if (!MN) {
146     setError(CurrentNode, "not a mapping");
147     return Ret;
148   }
149   for (auto &P : MN->Mapping)
150     Ret.push_back(P.first());
151   return Ret;
152 }
153 
154 bool Input::preflightKey(const char *Key, bool Required, bool, bool &UseDefault,
155                          void *&SaveInfo) {
156   UseDefault = false;
157   if (EC)
158     return false;
159 
160   // CurrentNode is null for empty documents, which is an error in case required
161   // nodes are present.
162   if (!CurrentNode) {
163     if (Required)
164       EC = make_error_code(errc::invalid_argument);
165     return false;
166   }
167 
168   MapHNode *MN = dyn_cast<MapHNode>(CurrentNode);
169   if (!MN) {
170     if (Required || !isa<EmptyHNode>(CurrentNode))
171       setError(CurrentNode, "not a mapping");
172     else
173       UseDefault = true;
174     return false;
175   }
176   MN->ValidKeys.push_back(Key);
177   HNode *Value = MN->Mapping[Key].first.get();
178   if (!Value) {
179     if (Required)
180       setError(CurrentNode, Twine("missing required key '") + Key + "'");
181     else
182       UseDefault = true;
183     return false;
184   }
185   SaveInfo = CurrentNode;
186   CurrentNode = Value;
187   return true;
188 }
189 
190 void Input::postflightKey(void *saveInfo) {
191   CurrentNode = reinterpret_cast<HNode *>(saveInfo);
192 }
193 
194 void Input::endMapping() {
195   if (EC)
196     return;
197   // CurrentNode can be null if the document is empty.
198   MapHNode *MN = dyn_cast_or_null<MapHNode>(CurrentNode);
199   if (!MN)
200     return;
201   for (const auto &NN : MN->Mapping) {
202     if (!is_contained(MN->ValidKeys, NN.first())) {
203       const SMRange &ReportLoc = NN.second.second;
204       if (!AllowUnknownKeys) {
205         setError(ReportLoc, Twine("unknown key '") + NN.first() + "'");
206         break;
207       } else
208         reportWarning(ReportLoc, Twine("unknown key '") + NN.first() + "'");
209     }
210   }
211 }
212 
213 void Input::beginFlowMapping() { beginMapping(); }
214 
215 void Input::endFlowMapping() { endMapping(); }
216 
217 unsigned Input::beginSequence() {
218   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode))
219     return SQ->Entries.size();
220   if (isa<EmptyHNode>(CurrentNode))
221     return 0;
222   // Treat case where there's a scalar "null" value as an empty sequence.
223   if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
224     if (isNull(SN->value()))
225       return 0;
226   }
227   // Any other type of HNode is an error.
228   setError(CurrentNode, "not a sequence");
229   return 0;
230 }
231 
232 void Input::endSequence() {
233 }
234 
235 bool Input::preflightElement(unsigned Index, void *&SaveInfo) {
236   if (EC)
237     return false;
238   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
239     SaveInfo = CurrentNode;
240     CurrentNode = SQ->Entries[Index].get();
241     return true;
242   }
243   return false;
244 }
245 
246 void Input::postflightElement(void *SaveInfo) {
247   CurrentNode = reinterpret_cast<HNode *>(SaveInfo);
248 }
249 
250 unsigned Input::beginFlowSequence() { return beginSequence(); }
251 
252 bool Input::preflightFlowElement(unsigned index, void *&SaveInfo) {
253   if (EC)
254     return false;
255   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
256     SaveInfo = CurrentNode;
257     CurrentNode = SQ->Entries[index].get();
258     return true;
259   }
260   return false;
261 }
262 
263 void Input::postflightFlowElement(void *SaveInfo) {
264   CurrentNode = reinterpret_cast<HNode *>(SaveInfo);
265 }
266 
267 void Input::endFlowSequence() {
268 }
269 
270 void Input::beginEnumScalar() {
271   ScalarMatchFound = false;
272 }
273 
274 bool Input::matchEnumScalar(const char *Str, bool) {
275   if (ScalarMatchFound)
276     return false;
277   if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
278     if (SN->value().equals(Str)) {
279       ScalarMatchFound = true;
280       return true;
281     }
282   }
283   return false;
284 }
285 
286 bool Input::matchEnumFallback() {
287   if (ScalarMatchFound)
288     return false;
289   ScalarMatchFound = true;
290   return true;
291 }
292 
293 void Input::endEnumScalar() {
294   if (!ScalarMatchFound) {
295     setError(CurrentNode, "unknown enumerated scalar");
296   }
297 }
298 
299 bool Input::beginBitSetScalar(bool &DoClear) {
300   BitValuesUsed.clear();
301   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
302     BitValuesUsed.resize(SQ->Entries.size());
303   } else {
304     setError(CurrentNode, "expected sequence of bit values");
305   }
306   DoClear = true;
307   return true;
308 }
309 
310 bool Input::bitSetMatch(const char *Str, bool) {
311   if (EC)
312     return false;
313   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
314     unsigned Index = 0;
315     for (auto &N : SQ->Entries) {
316       if (ScalarHNode *SN = dyn_cast<ScalarHNode>(N.get())) {
317         if (SN->value().equals(Str)) {
318           BitValuesUsed[Index] = true;
319           return true;
320         }
321       } else {
322         setError(CurrentNode, "unexpected scalar in sequence of bit values");
323       }
324       ++Index;
325     }
326   } else {
327     setError(CurrentNode, "expected sequence of bit values");
328   }
329   return false;
330 }
331 
332 void Input::endBitSetScalar() {
333   if (EC)
334     return;
335   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
336     assert(BitValuesUsed.size() == SQ->Entries.size());
337     for (unsigned i = 0; i < SQ->Entries.size(); ++i) {
338       if (!BitValuesUsed[i]) {
339         setError(SQ->Entries[i].get(), "unknown bit value");
340         return;
341       }
342     }
343   }
344 }
345 
346 void Input::scalarString(StringRef &S, QuotingType) {
347   if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
348     S = SN->value();
349   } else {
350     setError(CurrentNode, "unexpected scalar");
351   }
352 }
353 
354 void Input::blockScalarString(StringRef &S) { scalarString(S, QuotingType::None); }
355 
356 void Input::scalarTag(std::string &Tag) {
357   Tag = CurrentNode->_node->getVerbatimTag();
358 }
359 
360 void Input::setError(HNode *hnode, const Twine &message) {
361   assert(hnode && "HNode must not be NULL");
362   setError(hnode->_node, message);
363 }
364 
365 NodeKind Input::getNodeKind() {
366   if (isa<ScalarHNode>(CurrentNode))
367     return NodeKind::Scalar;
368   else if (isa<MapHNode>(CurrentNode))
369     return NodeKind::Map;
370   else if (isa<SequenceHNode>(CurrentNode))
371     return NodeKind::Sequence;
372   llvm_unreachable("Unsupported node kind");
373 }
374 
375 void Input::setError(Node *node, const Twine &message) {
376   Strm->printError(node, message);
377   EC = make_error_code(errc::invalid_argument);
378 }
379 
380 void Input::setError(const SMRange &range, const Twine &message) {
381   Strm->printError(range, message);
382   EC = make_error_code(errc::invalid_argument);
383 }
384 
385 void Input::reportWarning(HNode *hnode, const Twine &message) {
386   assert(hnode && "HNode must not be NULL");
387   Strm->printError(hnode->_node, message, SourceMgr::DK_Warning);
388 }
389 
390 void Input::reportWarning(Node *node, const Twine &message) {
391   Strm->printError(node, message, SourceMgr::DK_Warning);
392 }
393 
394 void Input::reportWarning(const SMRange &range, const Twine &message) {
395   Strm->printError(range, message, SourceMgr::DK_Warning);
396 }
397 
398 std::unique_ptr<Input::HNode> Input::createHNodes(Node *N) {
399   SmallString<128> StringStorage;
400   if (ScalarNode *SN = dyn_cast<ScalarNode>(N)) {
401     StringRef KeyStr = SN->getValue(StringStorage);
402     if (!StringStorage.empty()) {
403       // Copy string to permanent storage
404       KeyStr = StringStorage.str().copy(StringAllocator);
405     }
406     return std::make_unique<ScalarHNode>(N, KeyStr);
407   } else if (BlockScalarNode *BSN = dyn_cast<BlockScalarNode>(N)) {
408     StringRef ValueCopy = BSN->getValue().copy(StringAllocator);
409     return std::make_unique<ScalarHNode>(N, ValueCopy);
410   } else if (SequenceNode *SQ = dyn_cast<SequenceNode>(N)) {
411     auto SQHNode = std::make_unique<SequenceHNode>(N);
412     for (Node &SN : *SQ) {
413       auto Entry = createHNodes(&SN);
414       if (EC)
415         break;
416       SQHNode->Entries.push_back(std::move(Entry));
417     }
418     return std::move(SQHNode);
419   } else if (MappingNode *Map = dyn_cast<MappingNode>(N)) {
420     auto mapHNode = std::make_unique<MapHNode>(N);
421     for (KeyValueNode &KVN : *Map) {
422       Node *KeyNode = KVN.getKey();
423       ScalarNode *Key = dyn_cast_or_null<ScalarNode>(KeyNode);
424       Node *Value = KVN.getValue();
425       if (!Key || !Value) {
426         if (!Key)
427           setError(KeyNode, "Map key must be a scalar");
428         if (!Value)
429           setError(KeyNode, "Map value must not be empty");
430         break;
431       }
432       StringStorage.clear();
433       StringRef KeyStr = Key->getValue(StringStorage);
434       if (!StringStorage.empty()) {
435         // Copy string to permanent storage
436         KeyStr = StringStorage.str().copy(StringAllocator);
437       }
438       auto ValueHNode = createHNodes(Value);
439       if (EC)
440         break;
441       mapHNode->Mapping[KeyStr] =
442           std::make_pair(std::move(ValueHNode), KeyNode->getSourceRange());
443     }
444     return std::move(mapHNode);
445   } else if (isa<NullNode>(N)) {
446     return std::make_unique<EmptyHNode>(N);
447   } else {
448     setError(N, "unknown node kind");
449     return nullptr;
450   }
451 }
452 
453 void Input::setError(const Twine &Message) {
454   setError(CurrentNode, Message);
455 }
456 
457 void Input::setAllowUnknownKeys(bool Allow) { AllowUnknownKeys = Allow; }
458 
459 bool Input::canElideEmptySequence() {
460   return false;
461 }
462 
463 //===----------------------------------------------------------------------===//
464 //  Output
465 //===----------------------------------------------------------------------===//
466 
467 Output::Output(raw_ostream &yout, void *context, int WrapColumn)
468     : IO(context), Out(yout), WrapColumn(WrapColumn) {}
469 
470 Output::~Output() = default;
471 
472 bool Output::outputting() const {
473   return true;
474 }
475 
476 void Output::beginMapping() {
477   StateStack.push_back(inMapFirstKey);
478   PaddingBeforeContainer = Padding;
479   Padding = "\n";
480 }
481 
482 bool Output::mapTag(StringRef Tag, bool Use) {
483   if (Use) {
484     // If this tag is being written inside a sequence we should write the start
485     // of the sequence before writing the tag, otherwise the tag won't be
486     // attached to the element in the sequence, but rather the sequence itself.
487     bool SequenceElement = false;
488     if (StateStack.size() > 1) {
489       auto &E = StateStack[StateStack.size() - 2];
490       SequenceElement = inSeqAnyElement(E) || inFlowSeqAnyElement(E);
491     }
492     if (SequenceElement && StateStack.back() == inMapFirstKey) {
493       newLineCheck();
494     } else {
495       output(" ");
496     }
497     output(Tag);
498     if (SequenceElement) {
499       // If we're writing the tag during the first element of a map, the tag
500       // takes the place of the first element in the sequence.
501       if (StateStack.back() == inMapFirstKey) {
502         StateStack.pop_back();
503         StateStack.push_back(inMapOtherKey);
504       }
505       // Tags inside maps in sequences should act as keys in the map from a
506       // formatting perspective, so we always want a newline in a sequence.
507       Padding = "\n";
508     }
509   }
510   return Use;
511 }
512 
513 void Output::endMapping() {
514   // If we did not map anything, we should explicitly emit an empty map
515   if (StateStack.back() == inMapFirstKey) {
516     Padding = PaddingBeforeContainer;
517     newLineCheck();
518     output("{}");
519     Padding = "\n";
520   }
521   StateStack.pop_back();
522 }
523 
524 std::vector<StringRef> Output::keys() {
525   report_fatal_error("invalid call");
526 }
527 
528 bool Output::preflightKey(const char *Key, bool Required, bool SameAsDefault,
529                           bool &UseDefault, void *&SaveInfo) {
530   UseDefault = false;
531   SaveInfo = nullptr;
532   if (Required || !SameAsDefault || WriteDefaultValues) {
533     auto State = StateStack.back();
534     if (State == inFlowMapFirstKey || State == inFlowMapOtherKey) {
535       flowKey(Key);
536     } else {
537       newLineCheck();
538       paddedKey(Key);
539     }
540     return true;
541   }
542   return false;
543 }
544 
545 void Output::postflightKey(void *) {
546   if (StateStack.back() == inMapFirstKey) {
547     StateStack.pop_back();
548     StateStack.push_back(inMapOtherKey);
549   } else if (StateStack.back() == inFlowMapFirstKey) {
550     StateStack.pop_back();
551     StateStack.push_back(inFlowMapOtherKey);
552   }
553 }
554 
555 void Output::beginFlowMapping() {
556   StateStack.push_back(inFlowMapFirstKey);
557   newLineCheck();
558   ColumnAtMapFlowStart = Column;
559   output("{ ");
560 }
561 
562 void Output::endFlowMapping() {
563   StateStack.pop_back();
564   outputUpToEndOfLine(" }");
565 }
566 
567 void Output::beginDocuments() {
568   outputUpToEndOfLine("---");
569 }
570 
571 bool Output::preflightDocument(unsigned index) {
572   if (index > 0)
573     outputUpToEndOfLine("\n---");
574   return true;
575 }
576 
577 void Output::postflightDocument() {
578 }
579 
580 void Output::endDocuments() {
581   output("\n...\n");
582 }
583 
584 unsigned Output::beginSequence() {
585   StateStack.push_back(inSeqFirstElement);
586   PaddingBeforeContainer = Padding;
587   Padding = "\n";
588   return 0;
589 }
590 
591 void Output::endSequence() {
592   // If we did not emit anything, we should explicitly emit an empty sequence
593   if (StateStack.back() == inSeqFirstElement) {
594     Padding = PaddingBeforeContainer;
595     newLineCheck(/*EmptySequence=*/true);
596     output("[]");
597     Padding = "\n";
598   }
599   StateStack.pop_back();
600 }
601 
602 bool Output::preflightElement(unsigned, void *&SaveInfo) {
603   SaveInfo = nullptr;
604   return true;
605 }
606 
607 void Output::postflightElement(void *) {
608   if (StateStack.back() == inSeqFirstElement) {
609     StateStack.pop_back();
610     StateStack.push_back(inSeqOtherElement);
611   } else if (StateStack.back() == inFlowSeqFirstElement) {
612     StateStack.pop_back();
613     StateStack.push_back(inFlowSeqOtherElement);
614   }
615 }
616 
617 unsigned Output::beginFlowSequence() {
618   StateStack.push_back(inFlowSeqFirstElement);
619   newLineCheck();
620   ColumnAtFlowStart = Column;
621   output("[ ");
622   NeedFlowSequenceComma = false;
623   return 0;
624 }
625 
626 void Output::endFlowSequence() {
627   StateStack.pop_back();
628   outputUpToEndOfLine(" ]");
629 }
630 
631 bool Output::preflightFlowElement(unsigned, void *&SaveInfo) {
632   if (NeedFlowSequenceComma)
633     output(", ");
634   if (WrapColumn && Column > WrapColumn) {
635     output("\n");
636     for (int i = 0; i < ColumnAtFlowStart; ++i)
637       output(" ");
638     Column = ColumnAtFlowStart;
639     output("  ");
640   }
641   SaveInfo = nullptr;
642   return true;
643 }
644 
645 void Output::postflightFlowElement(void *) {
646   NeedFlowSequenceComma = true;
647 }
648 
649 void Output::beginEnumScalar() {
650   EnumerationMatchFound = false;
651 }
652 
653 bool Output::matchEnumScalar(const char *Str, bool Match) {
654   if (Match && !EnumerationMatchFound) {
655     newLineCheck();
656     outputUpToEndOfLine(Str);
657     EnumerationMatchFound = true;
658   }
659   return false;
660 }
661 
662 bool Output::matchEnumFallback() {
663   if (EnumerationMatchFound)
664     return false;
665   EnumerationMatchFound = true;
666   return true;
667 }
668 
669 void Output::endEnumScalar() {
670   if (!EnumerationMatchFound)
671     llvm_unreachable("bad runtime enum value");
672 }
673 
674 bool Output::beginBitSetScalar(bool &DoClear) {
675   newLineCheck();
676   output("[ ");
677   NeedBitValueComma = false;
678   DoClear = false;
679   return true;
680 }
681 
682 bool Output::bitSetMatch(const char *Str, bool Matches) {
683   if (Matches) {
684     if (NeedBitValueComma)
685       output(", ");
686     output(Str);
687     NeedBitValueComma = true;
688   }
689   return false;
690 }
691 
692 void Output::endBitSetScalar() {
693   outputUpToEndOfLine(" ]");
694 }
695 
696 void Output::scalarString(StringRef &S, QuotingType MustQuote) {
697   newLineCheck();
698   if (S.empty()) {
699     // Print '' for the empty string because leaving the field empty is not
700     // allowed.
701     outputUpToEndOfLine("''");
702     return;
703   }
704   if (MustQuote == QuotingType::None) {
705     // Only quote if we must.
706     outputUpToEndOfLine(S);
707     return;
708   }
709 
710   const char *const Quote = MustQuote == QuotingType::Single ? "'" : "\"";
711   output(Quote); // Starting quote.
712 
713   // When using double-quoted strings (and only in that case), non-printable characters may be
714   // present, and will be escaped using a variety of unicode-scalar and special short-form
715   // escapes. This is handled in yaml::escape.
716   if (MustQuote == QuotingType::Double) {
717     output(yaml::escape(S, /* EscapePrintable= */ false));
718     outputUpToEndOfLine(Quote);
719     return;
720   }
721 
722   unsigned i = 0;
723   unsigned j = 0;
724   unsigned End = S.size();
725   const char *Base = S.data();
726 
727   // When using single-quoted strings, any single quote ' must be doubled to be escaped.
728   while (j < End) {
729     if (S[j] == '\'') {                    // Escape quotes.
730       output(StringRef(&Base[i], j - i));  // "flush".
731       output(StringLiteral("''"));         // Print it as ''
732       i = j + 1;
733     }
734     ++j;
735   }
736   output(StringRef(&Base[i], j - i));
737   outputUpToEndOfLine(Quote); // Ending quote.
738 }
739 
740 void Output::blockScalarString(StringRef &S) {
741   if (!StateStack.empty())
742     newLineCheck();
743   output(" |");
744   outputNewLine();
745 
746   unsigned Indent = StateStack.empty() ? 1 : StateStack.size();
747 
748   auto Buffer = MemoryBuffer::getMemBuffer(S, "", false);
749   for (line_iterator Lines(*Buffer, false); !Lines.is_at_end(); ++Lines) {
750     for (unsigned I = 0; I < Indent; ++I) {
751       output("  ");
752     }
753     output(*Lines);
754     outputNewLine();
755   }
756 }
757 
758 void Output::scalarTag(std::string &Tag) {
759   if (Tag.empty())
760     return;
761   newLineCheck();
762   output(Tag);
763   output(" ");
764 }
765 
766 void Output::setError(const Twine &message) {
767 }
768 
769 bool Output::canElideEmptySequence() {
770   // Normally, with an optional key/value where the value is an empty sequence,
771   // the whole key/value can be not written.  But, that produces wrong yaml
772   // if the key/value is the only thing in the map and the map is used in
773   // a sequence.  This detects if the this sequence is the first key/value
774   // in map that itself is embedded in a sequence.
775   if (StateStack.size() < 2)
776     return true;
777   if (StateStack.back() != inMapFirstKey)
778     return true;
779   return !inSeqAnyElement(StateStack[StateStack.size() - 2]);
780 }
781 
782 void Output::output(StringRef s) {
783   Column += s.size();
784   Out << s;
785 }
786 
787 void Output::outputUpToEndOfLine(StringRef s) {
788   output(s);
789   if (StateStack.empty() || (!inFlowSeqAnyElement(StateStack.back()) &&
790                              !inFlowMapAnyKey(StateStack.back())))
791     Padding = "\n";
792 }
793 
794 void Output::outputNewLine() {
795   Out << "\n";
796   Column = 0;
797 }
798 
799 // if seq at top, indent as if map, then add "- "
800 // if seq in middle, use "- " if firstKey, else use "  "
801 //
802 
803 void Output::newLineCheck(bool EmptySequence) {
804   if (Padding != "\n") {
805     output(Padding);
806     Padding = {};
807     return;
808   }
809   outputNewLine();
810   Padding = {};
811 
812   if (StateStack.size() == 0 || EmptySequence)
813     return;
814 
815   unsigned Indent = StateStack.size() - 1;
816   bool OutputDash = false;
817 
818   if (StateStack.back() == inSeqFirstElement ||
819       StateStack.back() == inSeqOtherElement) {
820     OutputDash = true;
821   } else if ((StateStack.size() > 1) &&
822              ((StateStack.back() == inMapFirstKey) ||
823               inFlowSeqAnyElement(StateStack.back()) ||
824               (StateStack.back() == inFlowMapFirstKey)) &&
825              inSeqAnyElement(StateStack[StateStack.size() - 2])) {
826     --Indent;
827     OutputDash = true;
828   }
829 
830   for (unsigned i = 0; i < Indent; ++i) {
831     output("  ");
832   }
833   if (OutputDash) {
834     output("- ");
835   }
836 }
837 
838 void Output::paddedKey(StringRef key) {
839   output(key);
840   output(":");
841   const char *spaces = "                ";
842   if (key.size() < strlen(spaces))
843     Padding = &spaces[key.size()];
844   else
845     Padding = " ";
846 }
847 
848 void Output::flowKey(StringRef Key) {
849   if (StateStack.back() == inFlowMapOtherKey)
850     output(", ");
851   if (WrapColumn && Column > WrapColumn) {
852     output("\n");
853     for (int I = 0; I < ColumnAtMapFlowStart; ++I)
854       output(" ");
855     Column = ColumnAtMapFlowStart;
856     output("  ");
857   }
858   output(Key);
859   output(": ");
860 }
861 
862 NodeKind Output::getNodeKind() { report_fatal_error("invalid call"); }
863 
864 bool Output::inSeqAnyElement(InState State) {
865   return State == inSeqFirstElement || State == inSeqOtherElement;
866 }
867 
868 bool Output::inFlowSeqAnyElement(InState State) {
869   return State == inFlowSeqFirstElement || State == inFlowSeqOtherElement;
870 }
871 
872 bool Output::inMapAnyKey(InState State) {
873   return State == inMapFirstKey || State == inMapOtherKey;
874 }
875 
876 bool Output::inFlowMapAnyKey(InState State) {
877   return State == inFlowMapFirstKey || State == inFlowMapOtherKey;
878 }
879 
880 //===----------------------------------------------------------------------===//
881 //  traits for built-in types
882 //===----------------------------------------------------------------------===//
883 
884 void ScalarTraits<bool>::output(const bool &Val, void *, raw_ostream &Out) {
885   Out << (Val ? "true" : "false");
886 }
887 
888 StringRef ScalarTraits<bool>::input(StringRef Scalar, void *, bool &Val) {
889   if (llvm::Optional<bool> Parsed = parseBool(Scalar)) {
890     Val = *Parsed;
891     return StringRef();
892   }
893   return "invalid boolean";
894 }
895 
896 void ScalarTraits<StringRef>::output(const StringRef &Val, void *,
897                                      raw_ostream &Out) {
898   Out << Val;
899 }
900 
901 StringRef ScalarTraits<StringRef>::input(StringRef Scalar, void *,
902                                          StringRef &Val) {
903   Val = Scalar;
904   return StringRef();
905 }
906 
907 void ScalarTraits<std::string>::output(const std::string &Val, void *,
908                                        raw_ostream &Out) {
909   Out << Val;
910 }
911 
912 StringRef ScalarTraits<std::string>::input(StringRef Scalar, void *,
913                                            std::string &Val) {
914   Val = Scalar.str();
915   return StringRef();
916 }
917 
918 void ScalarTraits<uint8_t>::output(const uint8_t &Val, void *,
919                                    raw_ostream &Out) {
920   // use temp uin32_t because ostream thinks uint8_t is a character
921   uint32_t Num = Val;
922   Out << Num;
923 }
924 
925 StringRef ScalarTraits<uint8_t>::input(StringRef Scalar, void *, uint8_t &Val) {
926   unsigned long long n;
927   if (getAsUnsignedInteger(Scalar, 0, n))
928     return "invalid number";
929   if (n > 0xFF)
930     return "out of range number";
931   Val = n;
932   return StringRef();
933 }
934 
935 void ScalarTraits<uint16_t>::output(const uint16_t &Val, void *,
936                                     raw_ostream &Out) {
937   Out << Val;
938 }
939 
940 StringRef ScalarTraits<uint16_t>::input(StringRef Scalar, void *,
941                                         uint16_t &Val) {
942   unsigned long long n;
943   if (getAsUnsignedInteger(Scalar, 0, n))
944     return "invalid number";
945   if (n > 0xFFFF)
946     return "out of range number";
947   Val = n;
948   return StringRef();
949 }
950 
951 void ScalarTraits<uint32_t>::output(const uint32_t &Val, void *,
952                                     raw_ostream &Out) {
953   Out << Val;
954 }
955 
956 StringRef ScalarTraits<uint32_t>::input(StringRef Scalar, void *,
957                                         uint32_t &Val) {
958   unsigned long long n;
959   if (getAsUnsignedInteger(Scalar, 0, n))
960     return "invalid number";
961   if (n > 0xFFFFFFFFUL)
962     return "out of range number";
963   Val = n;
964   return StringRef();
965 }
966 
967 void ScalarTraits<uint64_t>::output(const uint64_t &Val, void *,
968                                     raw_ostream &Out) {
969   Out << Val;
970 }
971 
972 StringRef ScalarTraits<uint64_t>::input(StringRef Scalar, void *,
973                                         uint64_t &Val) {
974   unsigned long long N;
975   if (getAsUnsignedInteger(Scalar, 0, N))
976     return "invalid number";
977   Val = N;
978   return StringRef();
979 }
980 
981 void ScalarTraits<int8_t>::output(const int8_t &Val, void *, raw_ostream &Out) {
982   // use temp in32_t because ostream thinks int8_t is a character
983   int32_t Num = Val;
984   Out << Num;
985 }
986 
987 StringRef ScalarTraits<int8_t>::input(StringRef Scalar, void *, int8_t &Val) {
988   long long N;
989   if (getAsSignedInteger(Scalar, 0, N))
990     return "invalid number";
991   if ((N > 127) || (N < -128))
992     return "out of range number";
993   Val = N;
994   return StringRef();
995 }
996 
997 void ScalarTraits<int16_t>::output(const int16_t &Val, void *,
998                                    raw_ostream &Out) {
999   Out << Val;
1000 }
1001 
1002 StringRef ScalarTraits<int16_t>::input(StringRef Scalar, void *, int16_t &Val) {
1003   long long N;
1004   if (getAsSignedInteger(Scalar, 0, N))
1005     return "invalid number";
1006   if ((N > INT16_MAX) || (N < INT16_MIN))
1007     return "out of range number";
1008   Val = N;
1009   return StringRef();
1010 }
1011 
1012 void ScalarTraits<int32_t>::output(const int32_t &Val, void *,
1013                                    raw_ostream &Out) {
1014   Out << Val;
1015 }
1016 
1017 StringRef ScalarTraits<int32_t>::input(StringRef Scalar, void *, int32_t &Val) {
1018   long long N;
1019   if (getAsSignedInteger(Scalar, 0, N))
1020     return "invalid number";
1021   if ((N > INT32_MAX) || (N < INT32_MIN))
1022     return "out of range number";
1023   Val = N;
1024   return StringRef();
1025 }
1026 
1027 void ScalarTraits<int64_t>::output(const int64_t &Val, void *,
1028                                    raw_ostream &Out) {
1029   Out << Val;
1030 }
1031 
1032 StringRef ScalarTraits<int64_t>::input(StringRef Scalar, void *, int64_t &Val) {
1033   long long N;
1034   if (getAsSignedInteger(Scalar, 0, N))
1035     return "invalid number";
1036   Val = N;
1037   return StringRef();
1038 }
1039 
1040 void ScalarTraits<double>::output(const double &Val, void *, raw_ostream &Out) {
1041   Out << format("%g", Val);
1042 }
1043 
1044 StringRef ScalarTraits<double>::input(StringRef Scalar, void *, double &Val) {
1045   if (to_float(Scalar, Val))
1046     return StringRef();
1047   return "invalid floating point number";
1048 }
1049 
1050 void ScalarTraits<float>::output(const float &Val, void *, raw_ostream &Out) {
1051   Out << format("%g", Val);
1052 }
1053 
1054 StringRef ScalarTraits<float>::input(StringRef Scalar, void *, float &Val) {
1055   if (to_float(Scalar, Val))
1056     return StringRef();
1057   return "invalid floating point number";
1058 }
1059 
1060 void ScalarTraits<Hex8>::output(const Hex8 &Val, void *, raw_ostream &Out) {
1061   Out << format("0x%" PRIX8, (uint8_t)Val);
1062 }
1063 
1064 StringRef ScalarTraits<Hex8>::input(StringRef Scalar, void *, Hex8 &Val) {
1065   unsigned long long n;
1066   if (getAsUnsignedInteger(Scalar, 0, n))
1067     return "invalid hex8 number";
1068   if (n > 0xFF)
1069     return "out of range hex8 number";
1070   Val = n;
1071   return StringRef();
1072 }
1073 
1074 void ScalarTraits<Hex16>::output(const Hex16 &Val, void *, raw_ostream &Out) {
1075   Out << format("0x%" PRIX16, (uint16_t)Val);
1076 }
1077 
1078 StringRef ScalarTraits<Hex16>::input(StringRef Scalar, void *, Hex16 &Val) {
1079   unsigned long long n;
1080   if (getAsUnsignedInteger(Scalar, 0, n))
1081     return "invalid hex16 number";
1082   if (n > 0xFFFF)
1083     return "out of range hex16 number";
1084   Val = n;
1085   return StringRef();
1086 }
1087 
1088 void ScalarTraits<Hex32>::output(const Hex32 &Val, void *, raw_ostream &Out) {
1089   Out << format("0x%" PRIX32, (uint32_t)Val);
1090 }
1091 
1092 StringRef ScalarTraits<Hex32>::input(StringRef Scalar, void *, Hex32 &Val) {
1093   unsigned long long n;
1094   if (getAsUnsignedInteger(Scalar, 0, n))
1095     return "invalid hex32 number";
1096   if (n > 0xFFFFFFFFUL)
1097     return "out of range hex32 number";
1098   Val = n;
1099   return StringRef();
1100 }
1101 
1102 void ScalarTraits<Hex64>::output(const Hex64 &Val, void *, raw_ostream &Out) {
1103   Out << format("0x%" PRIX64, (uint64_t)Val);
1104 }
1105 
1106 StringRef ScalarTraits<Hex64>::input(StringRef Scalar, void *, Hex64 &Val) {
1107   unsigned long long Num;
1108   if (getAsUnsignedInteger(Scalar, 0, Num))
1109     return "invalid hex64 number";
1110   Val = Num;
1111   return StringRef();
1112 }
1113 
1114 void ScalarTraits<VersionTuple>::output(const VersionTuple &Val, void *,
1115                                         llvm::raw_ostream &Out) {
1116   Out << Val.getAsString();
1117 }
1118 
1119 StringRef ScalarTraits<VersionTuple>::input(StringRef Scalar, void *,
1120                                             VersionTuple &Val) {
1121   if (Val.tryParse(Scalar))
1122     return "invalid version format";
1123   return StringRef();
1124 }
1125