lib/Support/YAMLTraits.cpp

   1 //===- lib/Support/YAMLTraits.cpp -----------------------------------------===//
   2 //
   3 //                             The LLVM Linker
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/Support/YAMLTraits.h"
  11 #include "llvm/ADT/STLExtras.h"
  12 #include "llvm/ADT/SmallString.h"
  13 #include "llvm/ADT/StringExtras.h"
  14 #include "llvm/ADT/StringRef.h"
  15 #include "llvm/ADT/Twine.h"
  16 #include "llvm/Support/Casting.h"
  17 #include "llvm/Support/Errc.h"
  18 #include "llvm/Support/ErrorHandling.h"
  19 #include "llvm/Support/Format.h"
  20 #include "llvm/Support/LineIterator.h"
  21 #include "llvm/Support/MemoryBuffer.h"
  22 #include "llvm/Support/Unicode.h"
  23 #include "llvm/Support/YAMLParser.h"
  24 #include "llvm/Support/raw_ostream.h"
  25 #include <algorithm>
  26 #include <cassert>
  27 #include <cstdint>
  28 #include <cstdlib>
  29 #include <cstring>
  30 #include <string>
  31 #include <vector>
  32
  33 using namespace llvm;
  34 using namespace yaml;
  35
  36 //===----------------------------------------------------------------------===//
  37 //  IO
  38 //===----------------------------------------------------------------------===//
  39
  40 IO::IO(void *Context) : Ctxt(Context) {}
  41
  42 IO::~IO() = default;
  43
  44 void *IO::getContext() {
  45   return Ctxt;
  46 }
  47
  48 void IO::setContext(void *Context) {
  49   Ctxt = Context;
  50 }
  51
  52 //===----------------------------------------------------------------------===//
  53 //  Input
  54 //===----------------------------------------------------------------------===//
  55
  56 Input::Input(StringRef InputContent, void *Ctxt,
  57              SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt)
  58     : IO(Ctxt), Strm(new Stream(InputContent, SrcMgr, false, &EC)) {
  59   if (DiagHandler)
  60     SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt);
  61   DocIterator = Strm->begin();
  62 }
  63
  64 Input::Input(MemoryBufferRef Input, void *Ctxt,
  65              SourceMgr::DiagHandlerTy DiagHandler, void *DiagHandlerCtxt)
  66     : IO(Ctxt), Strm(new Stream(Input, SrcMgr, false, &EC)) {
  67   if (DiagHandler)
  68     SrcMgr.setDiagHandler(DiagHandler, DiagHandlerCtxt);
  69   DocIterator = Strm->begin();
  70 }
  71
  72 Input::~Input() = default;
  73
  74 std::error_code Input::error() { return EC; }
  75
  76 // Pin the vtables to this file.
  77 void Input::HNode::anchor() {}
  78 void Input::EmptyHNode::anchor() {}
  79 void Input::ScalarHNode::anchor() {}
  80 void Input::MapHNode::anchor() {}
  81 void Input::SequenceHNode::anchor() {}
  82
  83 bool Input::outputting() {
  84   return false;
  85 }
  86
  87 bool Input::setCurrentDocument() {
  88   if (DocIterator != Strm->end()) {
  89     Node *N = DocIterator->getRoot();
  90     if (!N) {
  91       assert(Strm->failed() && "Root is NULL iff parsing failed");
  92       EC = make_error_code(errc::invalid_argument);
  93       return false;
  94     }
  95
  96     if (isa<NullNode>(N)) {
  97       // Empty files are allowed and ignored
  98       ++DocIterator;
  99       return setCurrentDocument();
 100     }
 101     TopNode = this->createHNodes(N);
 102     CurrentNode = TopNode.get();
 103     return true;
 104   }
 105   return false;
 106 }
 107
 108 bool Input::nextDocument() {
 109   return ++DocIterator != Strm->end();
 110 }
 111
 112 const Node *Input::getCurrentNode() const {
 113   return CurrentNode ? CurrentNode->_node : nullptr;
 114 }
 115
 116 bool Input::mapTag(StringRef Tag, bool Default) {
 117   std::string foundTag = CurrentNode->_node->getVerbatimTag();
 118   if (foundTag.empty()) {
 119     // If no tag found and 'Tag' is the default, say it was found.
 120     return Default;
 121   }
 122   // Return true iff found tag matches supplied tag.
 123   return Tag.equals(foundTag);
 124 }
 125
 126 void Input::beginMapping() {
 127   if (EC)
 128     return;
 129   // CurrentNode can be null if the document is empty.
 130   MapHNode *MN = dyn_cast_or_null<MapHNode>(CurrentNode);
 131   if (MN) {
 132     MN->ValidKeys.clear();
 133   }
 134 }
 135
 136 std::vector<StringRef> Input::keys() {
 137   MapHNode *MN = dyn_cast<MapHNode>(CurrentNode);
 138   std::vector<StringRef> Ret;
 139   if (!MN) {
 140     setError(CurrentNode, "not a mapping");
 141     return Ret;
 142   }
 143   for (auto &P : MN->Mapping)
 144     Ret.push_back(P.first());
 145   return Ret;
 146 }
 147
 148 bool Input::preflightKey(const char *Key, bool Required, bool, bool &UseDefault,
 149                          void *&SaveInfo) {
 150   UseDefault = false;
 151   if (EC)
 152     return false;
 153
 154   // CurrentNode is null for empty documents, which is an error in case required
 155   // nodes are present.
 156   if (!CurrentNode) {
 157     if (Required)
 158       EC = make_error_code(errc::invalid_argument);
 159     return false;
 160   }
 161
 162   MapHNode *MN = dyn_cast<MapHNode>(CurrentNode);
 163   if (!MN) {
 164     if (Required || !isa<EmptyHNode>(CurrentNode))
 165       setError(CurrentNode, "not a mapping");
 166     return false;
 167   }
 168   MN->ValidKeys.push_back(Key);
 169   HNode *Value = MN->Mapping[Key].get();
 170   if (!Value) {
 171     if (Required)
 172       setError(CurrentNode, Twine("missing required key '") + Key + "'");
 173     else
 174       UseDefault = true;
 175     return false;
 176   }
 177   SaveInfo = CurrentNode;
 178   CurrentNode = Value;
 179   return true;
 180 }
 181
 182 void Input::postflightKey(void *saveInfo) {
 183   CurrentNode = reinterpret_cast<HNode *>(saveInfo);
 184 }
 185
 186 void Input::endMapping() {
 187   if (EC)
 188     return;
 189   // CurrentNode can be null if the document is empty.
 190   MapHNode *MN = dyn_cast_or_null<MapHNode>(CurrentNode);
 191   if (!MN)
 192     return;
 193   for (const auto &NN : MN->Mapping) {
 194     if (!is_contained(MN->ValidKeys, NN.first())) {
 195       setError(NN.second.get(), Twine("unknown key '") + NN.first() + "'");
 196       break;
 197     }
 198   }
 199 }
 200
 201 void Input::beginFlowMapping() { beginMapping(); }
 202
 203 void Input::endFlowMapping() { endMapping(); }
 204
 205 unsigned Input::beginSequence() {
 206   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode))
 207     return SQ->Entries.size();
 208   if (isa<EmptyHNode>(CurrentNode))
 209     return 0;
 210   // Treat case where there's a scalar "null" value as an empty sequence.
 211   if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
 212     if (isNull(SN->value()))
 213       return 0;
 214   }
 215   // Any other type of HNode is an error.
 216   setError(CurrentNode, "not a sequence");
 217   return 0;
 218 }
 219
 220 void Input::endSequence() {
 221 }
 222
 223 bool Input::preflightElement(unsigned Index, void *&SaveInfo) {
 224   if (EC)
 225     return false;
 226   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
 227     SaveInfo = CurrentNode;
 228     CurrentNode = SQ->Entries[Index].get();
 229     return true;
 230   }
 231   return false;
 232 }
 233
 234 void Input::postflightElement(void *SaveInfo) {
 235   CurrentNode = reinterpret_cast<HNode *>(SaveInfo);
 236 }
 237
 238 unsigned Input::beginFlowSequence() { return beginSequence(); }
 239
 240 bool Input::preflightFlowElement(unsigned index, void *&SaveInfo) {
 241   if (EC)
 242     return false;
 243   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
 244     SaveInfo = CurrentNode;
 245     CurrentNode = SQ->Entries[index].get();
 246     return true;
 247   }
 248   return false;
 249 }
 250
 251 void Input::postflightFlowElement(void *SaveInfo) {
 252   CurrentNode = reinterpret_cast<HNode *>(SaveInfo);
 253 }
 254
 255 void Input::endFlowSequence() {
 256 }
 257
 258 void Input::beginEnumScalar() {
 259   ScalarMatchFound = false;
 260 }
 261
 262 bool Input::matchEnumScalar(const char *Str, bool) {
 263   if (ScalarMatchFound)
 264     return false;
 265   if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
 266     if (SN->value().equals(Str)) {
 267       ScalarMatchFound = true;
 268       return true;
 269     }
 270   }
 271   return false;
 272 }
 273
 274 bool Input::matchEnumFallback() {
 275   if (ScalarMatchFound)
 276     return false;
 277   ScalarMatchFound = true;
 278   return true;
 279 }
 280
 281 void Input::endEnumScalar() {
 282   if (!ScalarMatchFound) {
 283     setError(CurrentNode, "unknown enumerated scalar");
 284   }
 285 }
 286
 287 bool Input::beginBitSetScalar(bool &DoClear) {
 288   BitValuesUsed.clear();
 289   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
 290     BitValuesUsed.insert(BitValuesUsed.begin(), SQ->Entries.size(), false);
 291   } else {
 292     setError(CurrentNode, "expected sequence of bit values");
 293   }
 294   DoClear = true;
 295   return true;
 296 }
 297
 298 bool Input::bitSetMatch(const char *Str, bool) {
 299   if (EC)
 300     return false;
 301   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
 302     unsigned Index = 0;
 303     for (auto &N : SQ->Entries) {
 304       if (ScalarHNode *SN = dyn_cast<ScalarHNode>(N.get())) {
 305         if (SN->value().equals(Str)) {
 306           BitValuesUsed[Index] = true;
 307           return true;
 308         }
 309       } else {
 310         setError(CurrentNode, "unexpected scalar in sequence of bit values");
 311       }
 312       ++Index;
 313     }
 314   } else {
 315     setError(CurrentNode, "expected sequence of bit values");
 316   }
 317   return false;
 318 }
 319
 320 void Input::endBitSetScalar() {
 321   if (EC)
 322     return;
 323   if (SequenceHNode *SQ = dyn_cast<SequenceHNode>(CurrentNode)) {
 324     assert(BitValuesUsed.size() == SQ->Entries.size());
 325     for (unsigned i = 0; i < SQ->Entries.size(); ++i) {
 326       if (!BitValuesUsed[i]) {
 327         setError(SQ->Entries[i].get(), "unknown bit value");
 328         return;
 329       }
 330     }
 331   }
 332 }
 333
 334 void Input::scalarString(StringRef &S, QuotingType) {
 335   if (ScalarHNode *SN = dyn_cast<ScalarHNode>(CurrentNode)) {
 336     S = SN->value();
 337   } else {
 338     setError(CurrentNode, "unexpected scalar");
 339   }
 340 }
 341
 342 void Input::blockScalarString(StringRef &S) { scalarString(S, QuotingType::None); }
 343
 344 void Input::setError(HNode *hnode, const Twine &message) {
 345   assert(hnode && "HNode must not be NULL");
 346   this->setError(hnode->_node, message);
 347 }
 348
 349 void Input::setError(Node *node, const Twine &message) {
 350   Strm->printError(node, message);
 351   EC = make_error_code(errc::invalid_argument);
 352 }
 353
 354 std::unique_ptr<Input::HNode> Input::createHNodes(Node *N) {
 355   SmallString<128> StringStorage;
 356   if (ScalarNode *SN = dyn_cast<ScalarNode>(N)) {
 357     StringRef KeyStr = SN->getValue(StringStorage);
 358     if (!StringStorage.empty()) {
 359       // Copy string to permanent storage
 360       KeyStr = StringStorage.str().copy(StringAllocator);
 361     }
 362     return llvm::make_unique<ScalarHNode>(N, KeyStr);
 363   } else if (BlockScalarNode *BSN = dyn_cast<BlockScalarNode>(N)) {
 364     StringRef ValueCopy = BSN->getValue().copy(StringAllocator);
 365     return llvm::make_unique<ScalarHNode>(N, ValueCopy);
 366   } else if (SequenceNode *SQ = dyn_cast<SequenceNode>(N)) {
 367     auto SQHNode = llvm::make_unique<SequenceHNode>(N);
 368     for (Node &SN : *SQ) {
 369       auto Entry = this->createHNodes(&SN);
 370       if (EC)
 371         break;
 372       SQHNode->Entries.push_back(std::move(Entry));
 373     }
 374     return std::move(SQHNode);
 375   } else if (MappingNode *Map = dyn_cast<MappingNode>(N)) {
 376     auto mapHNode = llvm::make_unique<MapHNode>(N);
 377     for (KeyValueNode &KVN : *Map) {
 378       Node *KeyNode = KVN.getKey();
 379       ScalarNode *Key = dyn_cast<ScalarNode>(KeyNode);
 380       Node *Value = KVN.getValue();
 381       if (!Key || !Value) {
 382         if (!Key)
 383           setError(KeyNode, "Map key must be a scalar");
 384         if (!Value)
 385           setError(KeyNode, "Map value must not be empty");
 386         break;
 387       }
 388       StringStorage.clear();
 389       StringRef KeyStr = Key->getValue(StringStorage);
 390       if (!StringStorage.empty()) {
 391         // Copy string to permanent storage
 392         KeyStr = StringStorage.str().copy(StringAllocator);
 393       }
 394       auto ValueHNode = this->createHNodes(Value);
 395       if (EC)
 396         break;
 397       mapHNode->Mapping[KeyStr] = std::move(ValueHNode);
 398     }
 399     return std::move(mapHNode);
 400   } else if (isa<NullNode>(N)) {
 401     return llvm::make_unique<EmptyHNode>(N);
 402   } else {
 403     setError(N, "unknown node kind");
 404     return nullptr;
 405   }
 406 }
 407
 408 void Input::setError(const Twine &Message) {
 409   this->setError(CurrentNode, Message);
 410 }
 411
 412 bool Input::canElideEmptySequence() {
 413   return false;
 414 }
 415
 416 //===----------------------------------------------------------------------===//
 417 //  Output
 418 //===----------------------------------------------------------------------===//
 419
 420 Output::Output(raw_ostream &yout, void *context, int WrapColumn)
 421     : IO(context), Out(yout), WrapColumn(WrapColumn) {}
 422
 423 Output::~Output() = default;
 424
 425 bool Output::outputting() {
 426   return true;
 427 }
 428
 429 void Output::beginMapping() {
 430   StateStack.push_back(inMapFirstKey);
 431   NeedsNewLine = true;
 432 }
 433
 434 bool Output::mapTag(StringRef Tag, bool Use) {
 435   if (Use) {
 436     // If this tag is being written inside a sequence we should write the start
 437     // of the sequence before writing the tag, otherwise the tag won't be
 438     // attached to the element in the sequence, but rather the sequence itself.
 439     bool SequenceElement =
 440         StateStack.size() > 1 && (StateStack[StateStack.size() - 2] == inSeq ||
 441           StateStack[StateStack.size() - 2] == inFlowSeq);
 442     if (SequenceElement && StateStack.back() == inMapFirstKey) {
 443       this->newLineCheck();
 444     } else {
 445       this->output(" ");
 446     }
 447     this->output(Tag);
 448     if (SequenceElement) {
 449       // If we're writing the tag during the first element of a map, the tag
 450       // takes the place of the first element in the sequence.
 451       if (StateStack.back() == inMapFirstKey) {
 452         StateStack.pop_back();
 453         StateStack.push_back(inMapOtherKey);
 454       }
 455       // Tags inside maps in sequences should act as keys in the map from a
 456       // formatting perspective, so we always want a newline in a sequence.
 457       NeedsNewLine = true;
 458     }
 459   }
 460   return Use;
 461 }
 462
 463 void Output::endMapping() {
 464   StateStack.pop_back();
 465 }
 466
 467 std::vector<StringRef> Output::keys() {
 468   report_fatal_error("invalid call");
 469 }
 470
 471 bool Output::preflightKey(const char *Key, bool Required, bool SameAsDefault,
 472                           bool &UseDefault, void *&) {
 473   UseDefault = false;
 474   if (Required || !SameAsDefault || WriteDefaultValues) {
 475     auto State = StateStack.back();
 476     if (State == inFlowMapFirstKey || State == inFlowMapOtherKey) {
 477       flowKey(Key);
 478     } else {
 479       this->newLineCheck();
 480       this->paddedKey(Key);
 481     }
 482     return true;
 483   }
 484   return false;
 485 }
 486
 487 void Output::postflightKey(void *) {
 488   if (StateStack.back() == inMapFirstKey) {
 489     StateStack.pop_back();
 490     StateStack.push_back(inMapOtherKey);
 491   } else if (StateStack.back() == inFlowMapFirstKey) {
 492     StateStack.pop_back();
 493     StateStack.push_back(inFlowMapOtherKey);
 494   }
 495 }
 496
 497 void Output::beginFlowMapping() {
 498   StateStack.push_back(inFlowMapFirstKey);
 499   this->newLineCheck();
 500   ColumnAtMapFlowStart = Column;
 501   output("{ ");
 502 }
 503
 504 void Output::endFlowMapping() {
 505   StateStack.pop_back();
 506   this->outputUpToEndOfLine(" }");
 507 }
 508
 509 void Output::beginDocuments() {
 510   this->outputUpToEndOfLine("---");
 511 }
 512
 513 bool Output::preflightDocument(unsigned index) {
 514   if (index > 0)
 515     this->outputUpToEndOfLine("\n---");
 516   return true;
 517 }
 518
 519 void Output::postflightDocument() {
 520 }
 521
 522 void Output::endDocuments() {
 523   output("\n...\n");
 524 }
 525
 526 unsigned Output::beginSequence() {
 527   StateStack.push_back(inSeq);
 528   NeedsNewLine = true;
 529   return 0;
 530 }
 531
 532 void Output::endSequence() {
 533   StateStack.pop_back();
 534 }
 535
 536 bool Output::preflightElement(unsigned, void *&) {
 537   return true;
 538 }
 539
 540 void Output::postflightElement(void *) {
 541 }
 542
 543 unsigned Output::beginFlowSequence() {
 544   StateStack.push_back(inFlowSeq);
 545   this->newLineCheck();
 546   ColumnAtFlowStart = Column;
 547   output("[ ");
 548   NeedFlowSequenceComma = false;
 549   return 0;
 550 }
 551
 552 void Output::endFlowSequence() {
 553   StateStack.pop_back();
 554   this->outputUpToEndOfLine(" ]");
 555 }
 556
 557 bool Output::preflightFlowElement(unsigned, void *&) {
 558   if (NeedFlowSequenceComma)
 559     output(", ");
 560   if (WrapColumn && Column > WrapColumn) {
 561     output("\n");
 562     for (int i = 0; i < ColumnAtFlowStart; ++i)
 563       output(" ");
 564     Column = ColumnAtFlowStart;
 565     output("  ");
 566   }
 567   return true;
 568 }
 569
 570 void Output::postflightFlowElement(void *) {
 571   NeedFlowSequenceComma = true;
 572 }
 573
 574 void Output::beginEnumScalar() {
 575   EnumerationMatchFound = false;
 576 }
 577
 578 bool Output::matchEnumScalar(const char *Str, bool Match) {
 579   if (Match && !EnumerationMatchFound) {
 580     this->newLineCheck();
 581     this->outputUpToEndOfLine(Str);
 582     EnumerationMatchFound = true;
 583   }
 584   return false;
 585 }
 586
 587 bool Output::matchEnumFallback() {
 588   if (EnumerationMatchFound)
 589     return false;
 590   EnumerationMatchFound = true;
 591   return true;
 592 }
 593
 594 void Output::endEnumScalar() {
 595   if (!EnumerationMatchFound)
 596     llvm_unreachable("bad runtime enum value");
 597 }
 598
 599 bool Output::beginBitSetScalar(bool &DoClear) {
 600   this->newLineCheck();
 601   output("[ ");
 602   NeedBitValueComma = false;
 603   DoClear = false;
 604   return true;
 605 }
 606
 607 bool Output::bitSetMatch(const char *Str, bool Matches) {
 608   if (Matches) {
 609     if (NeedBitValueComma)
 610       output(", ");
 611     this->output(Str);
 612     NeedBitValueComma = true;
 613   }
 614   return false;
 615 }
 616
 617 void Output::endBitSetScalar() {
 618   this->outputUpToEndOfLine(" ]");
 619 }
 620
 621 void Output::scalarString(StringRef &S, QuotingType MustQuote) {
 622   this->newLineCheck();
 623   if (S.empty()) {
 624     // Print '' for the empty string because leaving the field empty is not
 625     // allowed.
 626     this->outputUpToEndOfLine("''");
 627     return;
 628   }
 629   if (MustQuote == QuotingType::None) {
 630     // Only quote if we must.
 631     this->outputUpToEndOfLine(S);
 632     return;
 633   }
 634
 635   unsigned i = 0;
 636   unsigned j = 0;
 637   unsigned End = S.size();
 638   const char *Base = S.data();
 639
 640   const char *const Quote = MustQuote == QuotingType::Single ? "'" : "\"";
 641   output(Quote); // Starting quote.
 642
 643   // When using double-quoted strings (and only in that case), non-printable characters may be
 644   // present, and will be escaped using a variety of unicode-scalar and special short-form
 645   // escapes. This is handled in yaml::escape.
 646   if (MustQuote == QuotingType::Double) {
 647     output(yaml::escape(Base, /* EscapePrintable= */ false));
 648     this->outputUpToEndOfLine(Quote);
 649     return;
 650   }
 651
 652   // When using single-quoted strings, any single quote ' must be doubled to be escaped.
 653   while (j < End) {
 654     if (S[j] == '\'') {                    // Escape quotes.
 655       output(StringRef(&Base[i], j - i));  // "flush".
 656       output(StringLiteral("''"));         // Print it as ''
 657       i = j + 1;
 658     }
 659     ++j;
 660   }
 661   output(StringRef(&Base[i], j - i));
 662   this->outputUpToEndOfLine(Quote); // Ending quote.
 663 }
 664
 665 void Output::blockScalarString(StringRef &S) {
 666   if (!StateStack.empty())
 667     newLineCheck();
 668   output(" |");
 669   outputNewLine();
 670
 671   unsigned Indent = StateStack.empty() ? 1 : StateStack.size();
 672
 673   auto Buffer = MemoryBuffer::getMemBuffer(S, "", false);
 674   for (line_iterator Lines(*Buffer, false); !Lines.is_at_end(); ++Lines) {
 675     for (unsigned I = 0; I < Indent; ++I) {
 676       output("  ");
 677     }
 678     output(*Lines);
 679     outputNewLine();
 680   }
 681 }
 682
 683 void Output::setError(const Twine &message) {
 684 }
 685
 686 bool Output::canElideEmptySequence() {
 687   // Normally, with an optional key/value where the value is an empty sequence,
 688   // the whole key/value can be not written.  But, that produces wrong yaml
 689   // if the key/value is the only thing in the map and the map is used in
 690   // a sequence.  This detects if the this sequence is the first key/value
 691   // in map that itself is embedded in a sequnce.
 692   if (StateStack.size() < 2)
 693     return true;
 694   if (StateStack.back() != inMapFirstKey)
 695     return true;
 696   return (StateStack[StateStack.size()-2] != inSeq);
 697 }
 698
 699 void Output::output(StringRef s) {
 700   Column += s.size();
 701   Out << s;
 702 }
 703
 704 void Output::outputUpToEndOfLine(StringRef s) {
 705   this->output(s);
 706   if (StateStack.empty() || (StateStack.back() != inFlowSeq &&
 707                              StateStack.back() != inFlowMapFirstKey &&
 708                              StateStack.back() != inFlowMapOtherKey))
 709     NeedsNewLine = true;
 710 }
 711
 712 void Output::outputNewLine() {
 713   Out << "\n";
 714   Column = 0;
 715 }
 716
 717 // if seq at top, indent as if map, then add "- "
 718 // if seq in middle, use "- " if firstKey, else use "  "
 719 //
 720
 721 void Output::newLineCheck() {
 722   if (!NeedsNewLine)
 723     return;
 724   NeedsNewLine = false;
 725
 726   this->outputNewLine();
 727
 728   assert(StateStack.size() > 0);
 729   unsigned Indent = StateStack.size() - 1;
 730   bool OutputDash = false;
 731
 732   if (StateStack.back() == inSeq) {
 733     OutputDash = true;
 734   } else if ((StateStack.size() > 1) && ((StateStack.back() == inMapFirstKey) ||
 735              (StateStack.back() == inFlowSeq) ||
 736              (StateStack.back() == inFlowMapFirstKey)) &&
 737              (StateStack[StateStack.size() - 2] == inSeq)) {
 738     --Indent;
 739     OutputDash = true;
 740   }
 741
 742   for (unsigned i = 0; i < Indent; ++i) {
 743     output("  ");
 744   }
 745   if (OutputDash) {
 746     output("- ");
 747   }
 748
 749 }
 750
 751 void Output::paddedKey(StringRef key) {
 752   output(key);
 753   output(":");
 754   const char *spaces = "                ";
 755   if (key.size() < strlen(spaces))
 756     output(&spaces[key.size()]);
 757   else
 758     output(" ");
 759 }
 760
 761 void Output::flowKey(StringRef Key) {
 762   if (StateStack.back() == inFlowMapOtherKey)
 763     output(", ");
 764   if (WrapColumn && Column > WrapColumn) {
 765     output("\n");
 766     for (int I = 0; I < ColumnAtMapFlowStart; ++I)
 767       output(" ");
 768     Column = ColumnAtMapFlowStart;
 769     output("  ");
 770   }
 771   output(Key);
 772   output(": ");
 773 }
 774
 775 //===----------------------------------------------------------------------===//
 776 //  traits for built-in types
 777 //===----------------------------------------------------------------------===//
 778
 779 void ScalarTraits<bool>::output(const bool &Val, void *, raw_ostream &Out) {
 780   Out << (Val ? "true" : "false");
 781 }
 782
 783 StringRef ScalarTraits<bool>::input(StringRef Scalar, void *, bool &Val) {
 784   if (Scalar.equals("true")) {
 785     Val = true;
 786     return StringRef();
 787   } else if (Scalar.equals("false")) {
 788     Val = false;
 789     return StringRef();
 790   }
 791   return "invalid boolean";
 792 }
 793
 794 void ScalarTraits<StringRef>::output(const StringRef &Val, void *,
 795                                      raw_ostream &Out) {
 796   Out << Val;
 797 }
 798
 799 StringRef ScalarTraits<StringRef>::input(StringRef Scalar, void *,
 800                                          StringRef &Val) {
 801   Val = Scalar;
 802   return StringRef();
 803 }
 804
 805 void ScalarTraits<std::string>::output(const std::string &Val, void *,
 806                                      raw_ostream &Out) {
 807   Out << Val;
 808 }
 809
 810 StringRef ScalarTraits<std::string>::input(StringRef Scalar, void *,
 811                                          std::string &Val) {
 812   Val = Scalar.str();
 813   return StringRef();
 814 }
 815
 816 void ScalarTraits<uint8_t>::output(const uint8_t &Val, void *,
 817                                    raw_ostream &Out) {
 818   // use temp uin32_t because ostream thinks uint8_t is a character
 819   uint32_t Num = Val;
 820   Out << Num;
 821 }
 822
 823 StringRef ScalarTraits<uint8_t>::input(StringRef Scalar, void *, uint8_t &Val) {
 824   unsigned long long n;
 825   if (getAsUnsignedInteger(Scalar, 0, n))
 826     return "invalid number";
 827   if (n > 0xFF)
 828     return "out of range number";
 829   Val = n;
 830   return StringRef();
 831 }
 832
 833 void ScalarTraits<uint16_t>::output(const uint16_t &Val, void *,
 834                                     raw_ostream &Out) {
 835   Out << Val;
 836 }
 837
 838 StringRef ScalarTraits<uint16_t>::input(StringRef Scalar, void *,
 839                                         uint16_t &Val) {
 840   unsigned long long n;
 841   if (getAsUnsignedInteger(Scalar, 0, n))
 842     return "invalid number";
 843   if (n > 0xFFFF)
 844     return "out of range number";
 845   Val = n;
 846   return StringRef();
 847 }
 848
 849 void ScalarTraits<uint32_t>::output(const uint32_t &Val, void *,
 850                                     raw_ostream &Out) {
 851   Out << Val;
 852 }
 853
 854 StringRef ScalarTraits<uint32_t>::input(StringRef Scalar, void *,
 855                                         uint32_t &Val) {
 856   unsigned long long n;
 857   if (getAsUnsignedInteger(Scalar, 0, n))
 858     return "invalid number";
 859   if (n > 0xFFFFFFFFUL)
 860     return "out of range number";
 861   Val = n;
 862   return StringRef();
 863 }
 864
 865 void ScalarTraits<uint64_t>::output(const uint64_t &Val, void *,
 866                                     raw_ostream &Out) {
 867   Out << Val;
 868 }
 869
 870 StringRef ScalarTraits<uint64_t>::input(StringRef Scalar, void *,
 871                                         uint64_t &Val) {
 872   unsigned long long N;
 873   if (getAsUnsignedInteger(Scalar, 0, N))
 874     return "invalid number";
 875   Val = N;
 876   return StringRef();
 877 }
 878
 879 void ScalarTraits<int8_t>::output(const int8_t &Val, void *, raw_ostream &Out) {
 880   // use temp in32_t because ostream thinks int8_t is a character
 881   int32_t Num = Val;
 882   Out << Num;
 883 }
 884
 885 StringRef ScalarTraits<int8_t>::input(StringRef Scalar, void *, int8_t &Val) {
 886   long long N;
 887   if (getAsSignedInteger(Scalar, 0, N))
 888     return "invalid number";
 889   if ((N > 127) || (N < -128))
 890     return "out of range number";
 891   Val = N;
 892   return StringRef();
 893 }
 894
 895 void ScalarTraits<int16_t>::output(const int16_t &Val, void *,
 896                                    raw_ostream &Out) {
 897   Out << Val;
 898 }
 899
 900 StringRef ScalarTraits<int16_t>::input(StringRef Scalar, void *, int16_t &Val) {
 901   long long N;
 902   if (getAsSignedInteger(Scalar, 0, N))
 903     return "invalid number";
 904   if ((N > INT16_MAX) || (N < INT16_MIN))
 905     return "out of range number";
 906   Val = N;
 907   return StringRef();
 908 }
 909
 910 void ScalarTraits<int32_t>::output(const int32_t &Val, void *,
 911                                    raw_ostream &Out) {
 912   Out << Val;
 913 }
 914
 915 StringRef ScalarTraits<int32_t>::input(StringRef Scalar, void *, int32_t &Val) {
 916   long long N;
 917   if (getAsSignedInteger(Scalar, 0, N))
 918     return "invalid number";
 919   if ((N > INT32_MAX) || (N < INT32_MIN))
 920     return "out of range number";
 921   Val = N;
 922   return StringRef();
 923 }
 924
 925 void ScalarTraits<int64_t>::output(const int64_t &Val, void *,
 926                                    raw_ostream &Out) {
 927   Out << Val;
 928 }
 929
 930 StringRef ScalarTraits<int64_t>::input(StringRef Scalar, void *, int64_t &Val) {
 931   long long N;
 932   if (getAsSignedInteger(Scalar, 0, N))
 933     return "invalid number";
 934   Val = N;
 935   return StringRef();
 936 }
 937
 938 void ScalarTraits<double>::output(const double &Val, void *, raw_ostream &Out) {
 939   Out << format("%g", Val);
 940 }
 941
 942 StringRef ScalarTraits<double>::input(StringRef Scalar, void *, double &Val) {
 943   if (to_float(Scalar, Val))
 944     return StringRef();
 945   return "invalid floating point number";
 946 }
 947
 948 void ScalarTraits<float>::output(const float &Val, void *, raw_ostream &Out) {
 949   Out << format("%g", Val);
 950 }
 951
 952 StringRef ScalarTraits<float>::input(StringRef Scalar, void *, float &Val) {
 953   if (to_float(Scalar, Val))
 954     return StringRef();
 955   return "invalid floating point number";
 956 }
 957
 958 void ScalarTraits<Hex8>::output(const Hex8 &Val, void *, raw_ostream &Out) {
 959   uint8_t Num = Val;
 960   Out << format("0x%02X", Num);
 961 }
 962
 963 StringRef ScalarTraits<Hex8>::input(StringRef Scalar, void *, Hex8 &Val) {
 964   unsigned long long n;
 965   if (getAsUnsignedInteger(Scalar, 0, n))
 966     return "invalid hex8 number";
 967   if (n > 0xFF)
 968     return "out of range hex8 number";
 969   Val = n;
 970   return StringRef();
 971 }
 972
 973 void ScalarTraits<Hex16>::output(const Hex16 &Val, void *, raw_ostream &Out) {
 974   uint16_t Num = Val;
 975   Out << format("0x%04X", Num);
 976 }
 977
 978 StringRef ScalarTraits<Hex16>::input(StringRef Scalar, void *, Hex16 &Val) {
 979   unsigned long long n;
 980   if (getAsUnsignedInteger(Scalar, 0, n))
 981     return "invalid hex16 number";
 982   if (n > 0xFFFF)
 983     return "out of range hex16 number";
 984   Val = n;
 985   return StringRef();
 986 }
 987
 988 void ScalarTraits<Hex32>::output(const Hex32 &Val, void *, raw_ostream &Out) {
 989   uint32_t Num = Val;
 990   Out << format("0x%08X", Num);
 991 }
 992
 993 StringRef ScalarTraits<Hex32>::input(StringRef Scalar, void *, Hex32 &Val) {
 994   unsigned long long n;
 995   if (getAsUnsignedInteger(Scalar, 0, n))
 996     return "invalid hex32 number";
 997   if (n > 0xFFFFFFFFUL)
 998     return "out of range hex32 number";
 999   Val = n;
1000   return StringRef();
1001 }
1002
1003 void ScalarTraits<Hex64>::output(const Hex64 &Val, void *, raw_ostream &Out) {
1004   uint64_t Num = Val;
1005   Out << format("0x%016llX", Num);
1006 }
1007
1008 StringRef ScalarTraits<Hex64>::input(StringRef Scalar, void *, Hex64 &Val) {
1009   unsigned long long Num;
1010   if (getAsUnsignedInteger(Scalar, 0, Num))
1011     return "invalid hex64 number";
1012   Val = Num;
1013   return StringRef();
1014 }