llvm/tools/llvm-readtapi/DiffEngine.cpp

   1 //===-- DiffEngine.cpp - Structural file comparison -----------------------===//
   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 // This file defines the implementation of the llvm-tapi difference
  10 // engine, which structurally compares two tbd files.
  11 //
  12 //===----------------------------------------------------------------------===/
  13 #include "DiffEngine.h"
  14 #include "llvm/ADT/SmallString.h"
  15 #include "llvm/Support/Casting.h"
  16 #include "llvm/Support/raw_ostream.h"
  17 #include "llvm/TextAPI/InterfaceFile.h"
  18 #include "llvm/TextAPI/Symbol.h"
  19 #include "llvm/TextAPI/Target.h"
  20 #include <iterator>
  21
  22 using namespace llvm;
  23 using namespace MachO;
  24 using namespace object;
  25
  26 StringRef setOrderIndicator(InterfaceInputOrder Order) {
  27   return ((Order == lhs) ? "< " : "> ");
  28 }
  29
  30 // The following template specialization implementations
  31 // need to be explicitly placed into the llvm namespace
  32 // to work around a GCC 4.8 bug.
  33 namespace llvm {
  34
  35 template <typename T, DiffAttrKind U>
  36 inline void DiffScalarVal<T, U>::print(raw_ostream &OS, std::string Indent) {
  37   OS << Indent << "\t" << setOrderIndicator(Order) << Val << "\n";
  38 }
  39
  40 template <>
  41 inline void
  42 DiffScalarVal<StringRef, AD_Diff_Scalar_Str>::print(raw_ostream &OS,
  43                                                     std::string Indent) {
  44   OS << Indent << "\t\t" << setOrderIndicator(Order) << Val << "\n";
  45 }
  46
  47 template <>
  48 inline void
  49 DiffScalarVal<uint8_t, AD_Diff_Scalar_Unsigned>::print(raw_ostream &OS,
  50                                                        std::string Indent) {
  51   OS << Indent << "\t" << setOrderIndicator(Order) << std::to_string(Val)
  52      << "\n";
  53 }
  54
  55 template <>
  56 inline void
  57 DiffScalarVal<bool, AD_Diff_Scalar_Bool>::print(raw_ostream &OS,
  58                                                 std::string Indent) {
  59   OS << Indent << "\t" << setOrderIndicator(Order)
  60      << ((Val == true) ? "true" : "false") << "\n";
  61 }
  62
  63 } // end namespace llvm
  64
  65 StringLiteral SymScalar::getSymbolNamePrefix(MachO::SymbolKind Kind) {
  66   switch (Kind) {
  67   case MachO::SymbolKind::GlobalSymbol:
  68     return StringLiteral("");
  69   case MachO::SymbolKind::ObjectiveCClass:
  70     return ObjC2MetaClassNamePrefix;
  71   case MachO::SymbolKind ::ObjectiveCClassEHType:
  72     return ObjC2EHTypePrefix;
  73   case MachO::SymbolKind ::ObjectiveCInstanceVariable:
  74     return ObjC2IVarPrefix;
  75   }
  76   llvm_unreachable("Unknown llvm::MachO::SymbolKind enum");
  77 }
  78
  79 std::string SymScalar::getFlagString(const MachO::Symbol *Sym) {
  80   if (Sym->getFlags() == SymbolFlags::None)
  81     return {};
  82   SmallString<64> Flags(" - ");
  83   if (Sym->isThreadLocalValue())
  84     Flags.append("Thread-Local ");
  85   if (Sym->isWeakDefined())
  86     Flags.append("Weak-Defined ");
  87   if (Sym->isWeakReferenced())
  88     Flags.append("Weak-Referenced ");
  89   if (Sym->isUndefined())
  90     Flags.append("Undefined ");
  91   if (Sym->isReexported())
  92     Flags.append("Reexported ");
  93   if (Sym->isData())
  94     Flags.append("Data ");
  95   if (Sym->isText())
  96     Flags.append("Text ");
  97
  98   return std::string(Flags);
  99 }
 100
 101 void SymScalar::print(raw_ostream &OS, std::string Indent, MachO::Target Targ) {
 102   if (Val->getKind() == MachO::SymbolKind::ObjectiveCClass) {
 103     if (Targ.Arch == MachO::AK_i386 && Targ.Platform == MachO::PLATFORM_MACOS) {
 104       OS << Indent << "\t\t" << ((Order == lhs) ? "< " : "> ")
 105          << ObjC1ClassNamePrefix << Val->getName() << getFlagString(Val)
 106          << "\n";
 107       return;
 108     }
 109     OS << Indent << "\t\t" << ((Order == lhs) ? "< " : "> ")
 110        << ObjC2ClassNamePrefix << Val->getName() << getFlagString(Val) << "\n";
 111   }
 112   OS << Indent << "\t\t" << ((Order == lhs) ? "< " : "> ")
 113      << getSymbolNamePrefix(Val->getKind()) << Val->getName()
 114      << getFlagString(Val) << "\n";
 115 }
 116
 117 bool checkSymbolEquality(llvm::MachO::InterfaceFile::const_symbol_range LHS,
 118                          llvm::MachO::InterfaceFile::const_symbol_range RHS) {
 119   if (std::distance(LHS.begin(), LHS.end()) !=
 120       std::distance(RHS.begin(), RHS.end()))
 121     return false;
 122   return std::equal(LHS.begin(), LHS.end(), RHS.begin(),
 123                     [&](auto LHS, auto RHS) { return *LHS == *RHS; });
 124 }
 125
 126 template <typename TargetVecT, typename ValTypeT, typename V>
 127 void addDiffForTargSlice(V Val, Target Targ, DiffOutput &Diff,
 128                          InterfaceInputOrder Order) {
 129   auto TargetVector = llvm::find_if(
 130       Diff.Values, [&](const std::unique_ptr<AttributeDiff> &RawTVec) {
 131         if (TargetVecT *TVec = dyn_cast<TargetVecT>(RawTVec.get()))
 132           return TVec->Targ == Targ;
 133         return false;
 134       });
 135   if (TargetVector != Diff.Values.end()) {
 136     ValTypeT NewVal(Order, Val);
 137     cast<TargetVecT>(TargetVector->get())->TargValues.push_back(NewVal);
 138   } else {
 139     auto NewTargetVec = std::make_unique<TargetVecT>(Targ);
 140     ValTypeT NewVal(Order, Val);
 141     NewTargetVec->TargValues.push_back(NewVal);
 142     Diff.Values.push_back(std::move(NewTargetVec));
 143   }
 144 }
 145
 146 DiffOutput getSingleAttrDiff(const std::vector<InterfaceFileRef> &IRefVec,
 147                              std::string Name, InterfaceInputOrder Order) {
 148   DiffOutput Diff(Name);
 149   Diff.Kind = AD_Str_Vec;
 150   for (const auto &IRef : IRefVec)
 151     for (auto Targ : IRef.targets())
 152       addDiffForTargSlice<DiffStrVec,
 153                           DiffScalarVal<StringRef, AD_Diff_Scalar_Str>>(
 154           IRef.getInstallName(), Targ, Diff, Order);
 155   return Diff;
 156 }
 157
 158 DiffOutput
 159 getSingleAttrDiff(const std::vector<std::pair<Target, std::string>> &PairVec,
 160                   std::string Name, InterfaceInputOrder Order) {
 161   DiffOutput Diff(Name);
 162   Diff.Kind = AD_Str_Vec;
 163   for (const auto &Pair : PairVec)
 164     addDiffForTargSlice<DiffStrVec,
 165                         DiffScalarVal<StringRef, AD_Diff_Scalar_Str>>(
 166         StringRef(Pair.second), Pair.first, Diff, Order);
 167   return Diff;
 168 }
 169
 170 DiffOutput getSingleAttrDiff(InterfaceFile::const_symbol_range SymRange,
 171                              std::string Name, InterfaceInputOrder Order) {
 172   DiffOutput Diff(Name);
 173   Diff.Kind = AD_Sym_Vec;
 174   for (const auto *Sym : SymRange)
 175     for (auto Targ : Sym->targets())
 176       addDiffForTargSlice<DiffSymVec, SymScalar>(Sym, Targ, Diff, Order);
 177   return Diff;
 178 }
 179
 180 template <typename T>
 181 DiffOutput getSingleAttrDiff(T SingleAttr, std::string Attribute) {
 182   DiffOutput Diff(Attribute);
 183   Diff.Kind = SingleAttr.getKind();
 184   Diff.Values.push_back(std::make_unique<T>(SingleAttr));
 185   return Diff;
 186 }
 187
 188 template <typename T, DiffAttrKind U>
 189 void diffAttribute(std::string Name, std::vector<DiffOutput> &Output,
 190                    DiffScalarVal<T, U> Attr) {
 191   Output.push_back(getSingleAttrDiff(Attr, Name));
 192 }
 193
 194 template <typename T>
 195 void diffAttribute(std::string Name, std::vector<DiffOutput> &Output,
 196                    const T &Val, InterfaceInputOrder Order) {
 197   Output.push_back(getSingleAttrDiff(Val, Name, Order));
 198 }
 199
 200 std::vector<DiffOutput> getSingleIF(InterfaceFile *Interface,
 201                                     InterfaceInputOrder Order) {
 202   std::vector<DiffOutput> Output;
 203   diffAttribute("Install Name", Output,
 204                 DiffScalarVal<StringRef, AD_Diff_Scalar_Str>(
 205                     Order, Interface->getInstallName()));
 206   diffAttribute("Current Version", Output,
 207                 DiffScalarVal<PackedVersion, AD_Diff_Scalar_PackedVersion>(
 208                     Order, Interface->getCurrentVersion()));
 209   diffAttribute("Compatibility Version", Output,
 210                 DiffScalarVal<PackedVersion, AD_Diff_Scalar_PackedVersion>(
 211                     Order, Interface->getCompatibilityVersion()));
 212   diffAttribute("Swift ABI Version", Output,
 213                 DiffScalarVal<uint8_t, AD_Diff_Scalar_Unsigned>(
 214                     Order, Interface->getSwiftABIVersion()));
 215   diffAttribute("Two Level Namespace", Output,
 216                 DiffScalarVal<bool, AD_Diff_Scalar_Bool>(
 217                     Order, Interface->isTwoLevelNamespace()));
 218   diffAttribute("Application Extension Safe", Output,
 219                 DiffScalarVal<bool, AD_Diff_Scalar_Bool>(
 220                     Order, Interface->isApplicationExtensionSafe()));
 221   diffAttribute("Reexported Libraries", Output,
 222                 Interface->reexportedLibraries(), Order);
 223   diffAttribute("Allowable Clients", Output, Interface->allowableClients(),
 224                 Order);
 225   diffAttribute("Parent Umbrellas", Output, Interface->umbrellas(), Order);
 226   diffAttribute("Symbols", Output, Interface->symbols(), Order);
 227   for (const auto &Doc : Interface->documents()) {
 228     DiffOutput Documents("Inlined Reexported Frameworks/Libraries");
 229     Documents.Kind = AD_Inline_Doc;
 230     Documents.Values.push_back(std::make_unique<InlineDoc>(
 231         InlineDoc(Doc->getInstallName(), getSingleIF(Doc.get(), Order))));
 232     Output.push_back(std::move(Documents));
 233   }
 234   return Output;
 235 }
 236
 237 void findAndAddDiff(const std::vector<InterfaceFileRef> &CollectedIRefVec,
 238                     const std::vector<InterfaceFileRef> &LookupIRefVec,
 239                     DiffOutput &Result, InterfaceInputOrder Order) {
 240   Result.Kind = AD_Str_Vec;
 241   for (const auto &IRef : CollectedIRefVec)
 242     for (auto Targ : IRef.targets()) {
 243       auto FoundIRef = llvm::any_of(LookupIRefVec, [&](const auto LIRef) {
 244         return llvm::is_contained(LIRef.targets(), Targ) &&
 245                IRef.getInstallName() == LIRef.getInstallName();
 246       });
 247       if (!FoundIRef)
 248         addDiffForTargSlice<DiffStrVec,
 249                             DiffScalarVal<StringRef, AD_Diff_Scalar_Str>>(
 250             IRef.getInstallName(), Targ, Result, Order);
 251     }
 252 }
 253
 254 void findAndAddDiff(
 255     const std::vector<std::pair<Target, std::string>> &CollectedPairs,
 256     const std::vector<std::pair<Target, std::string>> &LookupPairs,
 257     DiffOutput &Result, InterfaceInputOrder Order) {
 258   Result.Kind = AD_Str_Vec;
 259   for (const auto &Pair : CollectedPairs) {
 260     auto FoundPair = llvm::find(LookupPairs, Pair);
 261     if (FoundPair == LookupPairs.end())
 262       addDiffForTargSlice<DiffStrVec,
 263                           DiffScalarVal<StringRef, AD_Diff_Scalar_Str>>(
 264           StringRef(Pair.second), Pair.first, Result, Order);
 265   }
 266 }
 267
 268 void findAndAddDiff(InterfaceFile::const_symbol_range CollectedSyms,
 269                     InterfaceFile::const_symbol_range LookupSyms,
 270                     DiffOutput &Result, InterfaceInputOrder Order) {
 271   Result.Kind = AD_Sym_Vec;
 272   for (const auto *Sym : CollectedSyms)
 273     for (const auto Targ : Sym->targets()) {
 274       auto FoundSym = llvm::any_of(LookupSyms, [&](const auto LSym) {
 275         return (Sym->getName() == LSym->getName() &&
 276                 Sym->getKind() == LSym->getKind() &&
 277                 Sym->getFlags() == LSym->getFlags() &&
 278                 llvm::is_contained(LSym->targets(), Targ));
 279       });
 280       if (!FoundSym)
 281         addDiffForTargSlice<DiffSymVec, SymScalar>(Sym, Targ, Result, Order);
 282     }
 283 }
 284
 285 template <typename T>
 286 DiffOutput recordDifferences(T LHS, T RHS, std::string Attr) {
 287   DiffOutput Diff(Attr);
 288   if (LHS.getKind() == RHS.getKind()) {
 289     Diff.Kind = LHS.getKind();
 290     Diff.Values.push_back(std::make_unique<T>(LHS));
 291     Diff.Values.push_back(std::make_unique<T>(RHS));
 292   }
 293   return Diff;
 294 }
 295
 296 template <typename T>
 297 DiffOutput recordDifferences(const std::vector<T> &LHS,
 298                              const std::vector<T> &RHS, std::string Attr) {
 299   DiffOutput Diff(Attr);
 300   Diff.Kind = AD_Str_Vec;
 301   findAndAddDiff(LHS, RHS, Diff, lhs);
 302   findAndAddDiff(RHS, LHS, Diff, rhs);
 303   return Diff;
 304 }
 305
 306 DiffOutput recordDifferences(llvm::MachO::InterfaceFile::const_symbol_range LHS,
 307                              llvm::MachO::InterfaceFile::const_symbol_range RHS,
 308                              std::string Attr) {
 309   DiffOutput Diff(Attr);
 310   Diff.Kind = AD_Sym_Vec;
 311   findAndAddDiff(LHS, RHS, Diff, lhs);
 312   findAndAddDiff(RHS, LHS, Diff, rhs);
 313   return Diff;
 314 }
 315
 316 std::vector<DiffOutput>
 317 DiffEngine::findDifferences(const InterfaceFile *IFLHS,
 318                             const InterfaceFile *IFRHS) {
 319   std::vector<DiffOutput> Output;
 320   if (IFLHS->getInstallName() != IFRHS->getInstallName())
 321     Output.push_back(recordDifferences(
 322         DiffScalarVal<StringRef, AD_Diff_Scalar_Str>(lhs,
 323                                                      IFLHS->getInstallName()),
 324         DiffScalarVal<StringRef, AD_Diff_Scalar_Str>(rhs,
 325                                                      IFRHS->getInstallName()),
 326         "Install Name"));
 327
 328   if (IFLHS->getCurrentVersion() != IFRHS->getCurrentVersion())
 329     Output.push_back(recordDifferences(
 330         DiffScalarVal<PackedVersion, AD_Diff_Scalar_PackedVersion>(
 331             lhs, IFLHS->getCurrentVersion()),
 332         DiffScalarVal<PackedVersion, AD_Diff_Scalar_PackedVersion>(
 333             rhs, IFRHS->getCurrentVersion()),
 334         "Current Version"));
 335   if (IFLHS->getCompatibilityVersion() != IFRHS->getCompatibilityVersion())
 336     Output.push_back(recordDifferences(
 337         DiffScalarVal<PackedVersion, AD_Diff_Scalar_PackedVersion>(
 338             lhs, IFLHS->getCompatibilityVersion()),
 339         DiffScalarVal<PackedVersion, AD_Diff_Scalar_PackedVersion>(
 340             rhs, IFRHS->getCompatibilityVersion()),
 341         "Compatibility Version"));
 342   if (IFLHS->getSwiftABIVersion() != IFRHS->getSwiftABIVersion())
 343     Output.push_back(
 344         recordDifferences(DiffScalarVal<uint8_t, AD_Diff_Scalar_Unsigned>(
 345                               lhs, IFLHS->getSwiftABIVersion()),
 346                           DiffScalarVal<uint8_t, AD_Diff_Scalar_Unsigned>(
 347                               rhs, IFRHS->getSwiftABIVersion()),
 348                           "Swift ABI Version"));
 349
 350   if (IFLHS->isTwoLevelNamespace() != IFRHS->isTwoLevelNamespace())
 351     Output.push_back(recordDifferences(DiffScalarVal<bool, AD_Diff_Scalar_Bool>(
 352                                            lhs, IFLHS->isTwoLevelNamespace()),
 353                                        DiffScalarVal<bool, AD_Diff_Scalar_Bool>(
 354                                            rhs, IFRHS->isTwoLevelNamespace()),
 355                                        "Two Level Namespace"));
 356
 357   if (IFLHS->isApplicationExtensionSafe() !=
 358       IFRHS->isApplicationExtensionSafe())
 359     Output.push_back(
 360         recordDifferences(DiffScalarVal<bool, AD_Diff_Scalar_Bool>(
 361                               lhs, IFLHS->isApplicationExtensionSafe()),
 362                           DiffScalarVal<bool, AD_Diff_Scalar_Bool>(
 363                               rhs, IFRHS->isApplicationExtensionSafe()),
 364                           "Application Extension Safe"));
 365
 366   if (IFLHS->hasSimulatorSupport() != IFRHS->hasSimulatorSupport())
 367     Output.push_back(recordDifferences(DiffScalarVal<bool, AD_Diff_Scalar_Bool>(
 368                                            lhs, IFLHS->hasSimulatorSupport()),
 369                                        DiffScalarVal<bool, AD_Diff_Scalar_Bool>(
 370                                            rhs, IFRHS->hasSimulatorSupport()),
 371                                        "Simulator Support"));
 372
 373   if (IFLHS->reexportedLibraries() != IFRHS->reexportedLibraries())
 374     Output.push_back(recordDifferences(IFLHS->reexportedLibraries(),
 375                                        IFRHS->reexportedLibraries(),
 376                                        "Reexported Libraries"));
 377
 378   if (IFLHS->rpaths() != IFRHS->rpaths())
 379     Output.push_back(recordDifferences(IFLHS->rpaths(), IFRHS->rpaths(),
 380                                        "Run Path Search Paths"));
 381
 382   if (IFLHS->allowableClients() != IFRHS->allowableClients())
 383     Output.push_back(recordDifferences(IFLHS->allowableClients(),
 384                                        IFRHS->allowableClients(),
 385                                        "Allowable Clients"));
 386
 387   if (IFLHS->umbrellas() != IFRHS->umbrellas())
 388     Output.push_back(recordDifferences(IFLHS->umbrellas(), IFRHS->umbrellas(),
 389                                        "Parent Umbrellas"));
 390
 391   if (!checkSymbolEquality(IFLHS->symbols(), IFRHS->symbols()))
 392     Output.push_back(
 393         recordDifferences(IFLHS->symbols(), IFRHS->symbols(), "Symbols"));
 394
 395   if (IFLHS->documents() != IFRHS->documents()) {
 396     DiffOutput Docs("Inlined Reexported Frameworks/Libraries");
 397     Docs.Kind = AD_Inline_Doc;
 398     std::vector<StringRef> DocsInserted;
 399     // Iterate through inline frameworks/libraries from interface file and find
 400     // match based on install name.
 401     for (auto DocLHS : IFLHS->documents()) {
 402       auto Pair = llvm::find_if(IFRHS->documents(), [&](const auto &DocRHS) {
 403         return (DocLHS->getInstallName() == DocRHS->getInstallName());
 404       });
 405       // If a match found, recursively get differences between the pair.
 406       if (Pair != IFRHS->documents().end()) {
 407         InlineDoc PairDiff =
 408             InlineDoc(DocLHS->getInstallName(),
 409                       findDifferences(DocLHS.get(), Pair->get()));
 410         if (!PairDiff.DocValues.empty())
 411           Docs.Values.push_back(
 412               std::make_unique<InlineDoc>(std::move(PairDiff)));
 413       }
 414       // If a match is not found, get attributes from single item.
 415       else
 416         Docs.Values.push_back(std::make_unique<InlineDoc>(InlineDoc(
 417             DocLHS->getInstallName(), getSingleIF(DocLHS.get(), lhs))));
 418       DocsInserted.push_back(DocLHS->getInstallName());
 419     }
 420     for (auto DocRHS : IFRHS->documents()) {
 421       auto WasGathered =
 422           llvm::any_of(DocsInserted, [&](const auto &GatheredDoc) {
 423             return (GatheredDoc == DocRHS->getInstallName());
 424           });
 425       if (!WasGathered)
 426         Docs.Values.push_back(std::make_unique<InlineDoc>(InlineDoc(
 427             DocRHS->getInstallName(), getSingleIF(DocRHS.get(), rhs))));
 428     }
 429     if (!Docs.Values.empty())
 430       Output.push_back(std::move(Docs));
 431   }
 432   return Output;
 433 }
 434
 435 template <typename T>
 436 void printSingleVal(std::string Indent, const DiffOutput &Attr,
 437                     raw_ostream &OS) {
 438   if (Attr.Values.empty())
 439     return;
 440   OS << Indent << Attr.Name << "\n";
 441   for (auto &RawItem : Attr.Values)
 442     if (T *Item = dyn_cast<T>(RawItem.get()))
 443       Item->print(OS, Indent);
 444 }
 445
 446 template <typename T>
 447 T *castValues(const std::unique_ptr<AttributeDiff> &RawAttr) {
 448   T *CastAttr = cast<T>(RawAttr.get());
 449   return CastAttr;
 450 }
 451
 452 template <typename T> void sortTargetValues(std::vector<T> &TargValues) {
 453   llvm::stable_sort(TargValues, [](const auto &ValA, const auto &ValB) {
 454     if (ValA.getOrder() == ValB.getOrder()) {
 455       return ValA.getVal() < ValB.getVal();
 456     }
 457     return ValA.getOrder() < ValB.getOrder();
 458   });
 459 }
 460
 461 template <typename T>
 462 void printVecVal(std::string Indent, const DiffOutput &Attr, raw_ostream &OS) {
 463   if (Attr.Values.empty())
 464     return;
 465
 466   OS << Indent << Attr.Name << "\n";
 467
 468   std::vector<T *> SortedAttrs;
 469
 470   llvm::transform(Attr.Values, std::back_inserter(SortedAttrs), castValues<T>);
 471
 472   llvm::sort(SortedAttrs, [&](const auto &ValA, const auto &ValB) {
 473     return ValA->Targ < ValB->Targ;
 474   });
 475
 476   for (auto *Vec : SortedAttrs) {
 477     sortTargetValues<DiffScalarVal<StringRef, AD_Diff_Scalar_Str>>(
 478         Vec->TargValues);
 479     OS << Indent << "\t" << getTargetTripleName(Vec->Targ) << "\n";
 480     for (auto &Item : Vec->TargValues)
 481       Item.print(OS, Indent);
 482   }
 483 }
 484
 485 template <>
 486 void printVecVal<DiffSymVec>(std::string Indent, const DiffOutput &Attr,
 487                              raw_ostream &OS) {
 488   if (Attr.Values.empty())
 489     return;
 490
 491   OS << Indent << Attr.Name << "\n";
 492
 493   std::vector<DiffSymVec *> SortedAttrs;
 494
 495   llvm::transform(Attr.Values, std::back_inserter(SortedAttrs),
 496                   castValues<DiffSymVec>);
 497
 498   llvm::sort(SortedAttrs, [&](const auto &ValA, const auto &ValB) {
 499     return ValA->Targ < ValB->Targ;
 500   });
 501   for (auto *SymVec : SortedAttrs) {
 502     sortTargetValues<SymScalar>(SymVec->TargValues);
 503     OS << Indent << "\t" << getTargetTripleName(SymVec->Targ) << "\n";
 504     for (auto &Item : SymVec->TargValues)
 505       Item.print(OS, Indent, SymVec->Targ);
 506   }
 507 }
 508
 509 void DiffEngine::printDifferences(raw_ostream &OS,
 510                                   const std::vector<DiffOutput> &Diffs,
 511                                   int IndentCounter) {
 512   std::string Indent = std::string(IndentCounter, '\t');
 513   for (auto &Attr : Diffs) {
 514     switch (Attr.Kind) {
 515     case AD_Diff_Scalar_Str:
 516       if (IndentCounter == 0)
 517         printSingleVal<DiffScalarVal<StringRef, AD_Diff_Scalar_Str>>(Indent,
 518                                                                      Attr, OS);
 519       break;
 520     case AD_Diff_Scalar_PackedVersion:
 521       printSingleVal<
 522           DiffScalarVal<PackedVersion, AD_Diff_Scalar_PackedVersion>>(Indent,
 523                                                                       Attr, OS);
 524       break;
 525     case AD_Diff_Scalar_Unsigned:
 526       printSingleVal<DiffScalarVal<uint8_t, AD_Diff_Scalar_Unsigned>>(Indent,
 527                                                                       Attr, OS);
 528       break;
 529     case AD_Diff_Scalar_Bool:
 530       printSingleVal<DiffScalarVal<bool, AD_Diff_Scalar_Bool>>(Indent, Attr,
 531                                                                OS);
 532       break;
 533     case AD_Str_Vec:
 534       printVecVal<DiffStrVec>(Indent, Attr, OS);
 535       break;
 536     case AD_Sym_Vec:
 537       printVecVal<DiffSymVec>(Indent, Attr, OS);
 538       break;
 539     case AD_Inline_Doc:
 540       if (!Attr.Values.empty()) {
 541         OS << Indent << Attr.Name << "\n";
 542         for (auto &Item : Attr.Values)
 543           if (InlineDoc *Doc = dyn_cast<InlineDoc>(Item.get()))
 544             if (!Doc->DocValues.empty()) {
 545               OS << Indent << "\t" << Doc->InstallName << "\n";
 546               printDifferences(OS, std::move(Doc->DocValues), 2);
 547             }
 548       }
 549       break;
 550     }
 551   }
 552 }
 553
 554 bool DiffEngine::compareFiles(raw_ostream &OS) {
 555   const auto *IFLHS = &(FileLHS->getInterfaceFile());
 556   const auto *IFRHS = &(FileRHS->getInterfaceFile());
 557   if (*IFLHS == *IFRHS)
 558     return false;
 559   OS << "< " << std::string(IFLHS->getPath().data()) << "\n> "
 560      << std::string(IFRHS->getPath().data()) << "\n\n";
 561   std::vector<DiffOutput> Diffs = findDifferences(IFLHS, IFRHS);
 562   printDifferences(OS, Diffs, 0);
 563   return true;
 564 }