clang/lib/Lex/InitHeaderSearch.cpp

   1 //===--- InitHeaderSearch.cpp - Initialize header search paths ------------===//
   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 implements the InitHeaderSearch class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "clang/Basic/DiagnosticFrontend.h"
  14 #include "clang/Basic/FileManager.h"
  15 #include "clang/Basic/LangOptions.h"
  16 #include "clang/Config/config.h" // C_INCLUDE_DIRS
  17 #include "clang/Lex/HeaderMap.h"
  18 #include "clang/Lex/HeaderSearch.h"
  19 #include "clang/Lex/HeaderSearchOptions.h"
  20 #include "llvm/ADT/SmallPtrSet.h"
  21 #include "llvm/ADT/SmallString.h"
  22 #include "llvm/ADT/SmallVector.h"
  23 #include "llvm/ADT/StringExtras.h"
  24 #include "llvm/ADT/Twine.h"
  25 #include "llvm/Support/ErrorHandling.h"
  26 #include "llvm/Support/Path.h"
  27 #include "llvm/Support/raw_ostream.h"
  28 #include "llvm/TargetParser/Triple.h"
  29 #include <optional>
  30
  31 using namespace clang;
  32 using namespace clang::frontend;
  33
  34 namespace {
  35 /// Holds information about a single DirectoryLookup object.
  36 struct DirectoryLookupInfo {
  37   IncludeDirGroup Group;
  38   DirectoryLookup Lookup;
  39   std::optional<unsigned> UserEntryIdx;
  40
  41   DirectoryLookupInfo(IncludeDirGroup Group, DirectoryLookup Lookup,
  42                       std::optional<unsigned> UserEntryIdx)
  43       : Group(Group), Lookup(Lookup), UserEntryIdx(UserEntryIdx) {}
  44 };
  45
  46 /// This class makes it easier to set the search paths of a HeaderSearch object.
  47 /// InitHeaderSearch stores several search path lists internally, which can be
  48 /// sent to a HeaderSearch object in one swoop.
  49 class InitHeaderSearch {
  50   std::vector<DirectoryLookupInfo> IncludePath;
  51   std::vector<std::pair<std::string, bool> > SystemHeaderPrefixes;
  52   HeaderSearch &Headers;
  53   bool Verbose;
  54   std::string IncludeSysroot;
  55   bool HasSysroot;
  56
  57 public:
  58   InitHeaderSearch(HeaderSearch &HS, bool verbose, StringRef sysroot)
  59       : Headers(HS), Verbose(verbose), IncludeSysroot(std::string(sysroot)),
  60         HasSysroot(!(sysroot.empty() || sysroot == "/")) {}
  61
  62   /// Add the specified path to the specified group list, prefixing the sysroot
  63   /// if used.
  64   /// Returns true if the path exists, false if it was ignored.
  65   bool AddPath(const Twine &Path, IncludeDirGroup Group, bool isFramework,
  66                std::optional<unsigned> UserEntryIdx = std::nullopt);
  67
  68   /// Add the specified path to the specified group list, without performing any
  69   /// sysroot remapping.
  70   /// Returns true if the path exists, false if it was ignored.
  71   bool AddUnmappedPath(const Twine &Path, IncludeDirGroup Group,
  72                        bool isFramework,
  73                        std::optional<unsigned> UserEntryIdx = std::nullopt);
  74
  75   /// Add the specified prefix to the system header prefix list.
  76   void AddSystemHeaderPrefix(StringRef Prefix, bool IsSystemHeader) {
  77     SystemHeaderPrefixes.emplace_back(std::string(Prefix), IsSystemHeader);
  78   }
  79
  80   /// Add the necessary paths to support a MinGW libstdc++.
  81   void AddMinGWCPlusPlusIncludePaths(StringRef Base,
  82                                      StringRef Arch,
  83                                      StringRef Version);
  84
  85   /// Add paths that should always be searched.
  86   void AddDefaultCIncludePaths(const llvm::Triple &triple,
  87                                const HeaderSearchOptions &HSOpts);
  88
  89   /// Add paths that should be searched when compiling c++.
  90   void AddDefaultCPlusPlusIncludePaths(const LangOptions &LangOpts,
  91                                        const llvm::Triple &triple,
  92                                        const HeaderSearchOptions &HSOpts);
  93
  94   /// Returns true iff AddDefaultIncludePaths should do anything.  If this
  95   /// returns false, include paths should instead be handled in the driver.
  96   bool ShouldAddDefaultIncludePaths(const llvm::Triple &triple);
  97
  98   /// Adds the default system include paths so that e.g. stdio.h is found.
  99   void AddDefaultIncludePaths(const LangOptions &Lang,
 100                               const llvm::Triple &triple,
 101                               const HeaderSearchOptions &HSOpts);
 102
 103   /// Merges all search path lists into one list and send it to HeaderSearch.
 104   void Realize(const LangOptions &Lang);
 105 };
 106
 107 }  // end anonymous namespace.
 108
 109 static bool CanPrefixSysroot(StringRef Path) {
 110 #if defined(_WIN32)
 111   return !Path.empty() && llvm::sys::path::is_separator(Path[0]);
 112 #else
 113   return llvm::sys::path::is_absolute(Path);
 114 #endif
 115 }
 116
 117 bool InitHeaderSearch::AddPath(const Twine &Path, IncludeDirGroup Group,
 118                                bool isFramework,
 119                                std::optional<unsigned> UserEntryIdx) {
 120   // Add the path with sysroot prepended, if desired and this is a system header
 121   // group.
 122   if (HasSysroot) {
 123     SmallString<256> MappedPathStorage;
 124     StringRef MappedPathStr = Path.toStringRef(MappedPathStorage);
 125     if (CanPrefixSysroot(MappedPathStr)) {
 126       return AddUnmappedPath(IncludeSysroot + Path, Group, isFramework,
 127                              UserEntryIdx);
 128     }
 129   }
 130
 131   return AddUnmappedPath(Path, Group, isFramework, UserEntryIdx);
 132 }
 133
 134 bool InitHeaderSearch::AddUnmappedPath(const Twine &Path, IncludeDirGroup Group,
 135                                        bool isFramework,
 136                                        std::optional<unsigned> UserEntryIdx) {
 137   assert(!Path.isTriviallyEmpty() && "can't handle empty path here");
 138
 139   FileManager &FM = Headers.getFileMgr();
 140   SmallString<256> MappedPathStorage;
 141   StringRef MappedPathStr = Path.toStringRef(MappedPathStorage);
 142
 143   // If use system headers while cross-compiling, emit the warning.
 144   if (HasSysroot && (MappedPathStr.startswith("/usr/include") ||
 145                      MappedPathStr.startswith("/usr/local/include"))) {
 146     Headers.getDiags().Report(diag::warn_poison_system_directories)
 147         << MappedPathStr;
 148   }
 149
 150   // Compute the DirectoryLookup type.
 151   SrcMgr::CharacteristicKind Type;
 152   if (Group == Quoted || Group == Angled || Group == IndexHeaderMap) {
 153     Type = SrcMgr::C_User;
 154   } else if (Group == ExternCSystem) {
 155     Type = SrcMgr::C_ExternCSystem;
 156   } else {
 157     Type = SrcMgr::C_System;
 158   }
 159
 160   // If the directory exists, add it.
 161   if (auto DE = FM.getOptionalDirectoryRef(MappedPathStr)) {
 162     IncludePath.emplace_back(Group, DirectoryLookup(*DE, Type, isFramework),
 163                              UserEntryIdx);
 164     return true;
 165   }
 166
 167   // Check to see if this is an apple-style headermap (which are not allowed to
 168   // be frameworks).
 169   if (!isFramework) {
 170     if (auto FE = FM.getOptionalFileRef(MappedPathStr)) {
 171       if (const HeaderMap *HM = Headers.CreateHeaderMap(*FE)) {
 172         // It is a headermap, add it to the search path.
 173         IncludePath.emplace_back(
 174             Group, DirectoryLookup(HM, Type, Group == IndexHeaderMap),
 175             UserEntryIdx);
 176         return true;
 177       }
 178     }
 179   }
 180
 181   if (Verbose)
 182     llvm::errs() << "ignoring nonexistent directory \""
 183                  << MappedPathStr << "\"\n";
 184   return false;
 185 }
 186
 187 void InitHeaderSearch::AddMinGWCPlusPlusIncludePaths(StringRef Base,
 188                                                      StringRef Arch,
 189                                                      StringRef Version) {
 190   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++",
 191           CXXSystem, false);
 192   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++/" + Arch,
 193           CXXSystem, false);
 194   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++/backward",
 195           CXXSystem, false);
 196 }
 197
 198 void InitHeaderSearch::AddDefaultCIncludePaths(const llvm::Triple &triple,
 199                                             const HeaderSearchOptions &HSOpts) {
 200   if (!ShouldAddDefaultIncludePaths(triple))
 201     llvm_unreachable("Include management is handled in the driver.");
 202
 203   llvm::Triple::OSType os = triple.getOS();
 204
 205   if (HSOpts.UseStandardSystemIncludes) {
 206     switch (os) {
 207     case llvm::Triple::Win32:
 208       if (triple.getEnvironment() != llvm::Triple::Cygnus)
 209         break;
 210       [[fallthrough]];
 211     default:
 212       // FIXME: temporary hack: hard-coded paths.
 213       AddPath("/usr/local/include", System, false);
 214       break;
 215     }
 216   }
 217
 218   // Builtin includes use #include_next directives and should be positioned
 219   // just prior C include dirs.
 220   if (HSOpts.UseBuiltinIncludes) {
 221     // Ignore the sys root, we *always* look for clang headers relative to
 222     // supplied path.
 223     SmallString<128> P = StringRef(HSOpts.ResourceDir);
 224     llvm::sys::path::append(P, "include");
 225     AddUnmappedPath(P, ExternCSystem, false);
 226   }
 227
 228   // All remaining additions are for system include directories, early exit if
 229   // we aren't using them.
 230   if (!HSOpts.UseStandardSystemIncludes)
 231     return;
 232
 233   // Add dirs specified via 'configure --with-c-include-dirs'.
 234   StringRef CIncludeDirs(C_INCLUDE_DIRS);
 235   if (CIncludeDirs != "") {
 236     SmallVector<StringRef, 5> dirs;
 237     CIncludeDirs.split(dirs, ":");
 238     for (StringRef dir : dirs)
 239       AddPath(dir, ExternCSystem, false);
 240     return;
 241   }
 242
 243   switch (os) {
 244   case llvm::Triple::Win32:
 245     switch (triple.getEnvironment()) {
 246     default: llvm_unreachable("Include management is handled in the driver.");
 247     case llvm::Triple::Cygnus:
 248       AddPath("/usr/include/w32api", System, false);
 249       break;
 250     case llvm::Triple::GNU:
 251       break;
 252     }
 253     break;
 254   default:
 255     break;
 256   }
 257
 258   AddPath("/usr/include", ExternCSystem, false);
 259 }
 260
 261 void InitHeaderSearch::AddDefaultCPlusPlusIncludePaths(
 262     const LangOptions &LangOpts, const llvm::Triple &triple,
 263     const HeaderSearchOptions &HSOpts) {
 264   if (!ShouldAddDefaultIncludePaths(triple))
 265     llvm_unreachable("Include management is handled in the driver.");
 266
 267   // FIXME: temporary hack: hard-coded paths.
 268   llvm::Triple::OSType os = triple.getOS();
 269   switch (os) {
 270   case llvm::Triple::Win32:
 271     switch (triple.getEnvironment()) {
 272     default: llvm_unreachable("Include management is handled in the driver.");
 273     case llvm::Triple::Cygnus:
 274       // Cygwin-1.7
 275       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.7.3");
 276       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.5.3");
 277       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.4");
 278       // g++-4 / Cygwin-1.5
 279       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.2");
 280       break;
 281     }
 282     break;
 283   default:
 284     break;
 285   }
 286 }
 287
 288 bool InitHeaderSearch::ShouldAddDefaultIncludePaths(
 289     const llvm::Triple &triple) {
 290   switch (triple.getOS()) {
 291   case llvm::Triple::AIX:
 292   case llvm::Triple::DragonFly:
 293   case llvm::Triple::ELFIAMCU:
 294   case llvm::Triple::Emscripten:
 295   case llvm::Triple::FreeBSD:
 296   case llvm::Triple::Fuchsia:
 297   case llvm::Triple::Haiku:
 298   case llvm::Triple::Hurd:
 299   case llvm::Triple::Linux:
 300   case llvm::Triple::LiteOS:
 301   case llvm::Triple::NaCl:
 302   case llvm::Triple::NetBSD:
 303   case llvm::Triple::OpenBSD:
 304   case llvm::Triple::PS4:
 305   case llvm::Triple::PS5:
 306   case llvm::Triple::RTEMS:
 307   case llvm::Triple::Solaris:
 308   case llvm::Triple::WASI:
 309   case llvm::Triple::ZOS:
 310     return false;
 311
 312   case llvm::Triple::Win32:
 313     if (triple.getEnvironment() != llvm::Triple::Cygnus ||
 314         triple.isOSBinFormatMachO())
 315       return false;
 316     break;
 317
 318   case llvm::Triple::UnknownOS:
 319     if (triple.isWasm())
 320       return false;
 321     break;
 322
 323   default:
 324     break;
 325   }
 326
 327   return true; // Everything else uses AddDefaultIncludePaths().
 328 }
 329
 330 void InitHeaderSearch::AddDefaultIncludePaths(
 331     const LangOptions &Lang, const llvm::Triple &triple,
 332     const HeaderSearchOptions &HSOpts) {
 333   // NB: This code path is going away. All of the logic is moving into the
 334   // driver which has the information necessary to do target-specific
 335   // selections of default include paths. Each target which moves there will be
 336   // exempted from this logic in ShouldAddDefaultIncludePaths() until we can
 337   // delete the entire pile of code.
 338   if (!ShouldAddDefaultIncludePaths(triple))
 339     return;
 340
 341   // NOTE: some additional header search logic is handled in the driver for
 342   // Darwin.
 343   if (triple.isOSDarwin()) {
 344     if (HSOpts.UseStandardSystemIncludes) {
 345       // Add the default framework include paths on Darwin.
 346       if (triple.isDriverKit()) {
 347         AddPath("/System/DriverKit/System/Library/Frameworks", System, true);
 348       } else {
 349         AddPath("/System/Library/Frameworks", System, true);
 350         AddPath("/Library/Frameworks", System, true);
 351       }
 352     }
 353     return;
 354   }
 355
 356   if (Lang.CPlusPlus && !Lang.AsmPreprocessor &&
 357       HSOpts.UseStandardCXXIncludes && HSOpts.UseStandardSystemIncludes) {
 358     if (HSOpts.UseLibcxx) {
 359       AddPath("/usr/include/c++/v1", CXXSystem, false);
 360     } else {
 361       AddDefaultCPlusPlusIncludePaths(Lang, triple, HSOpts);
 362     }
 363   }
 364
 365   AddDefaultCIncludePaths(triple, HSOpts);
 366 }
 367
 368 /// If there are duplicate directory entries in the specified search list,
 369 /// remove the later (dead) ones.  Returns the number of non-system headers
 370 /// removed, which is used to update NumAngled.
 371 static unsigned RemoveDuplicates(std::vector<DirectoryLookupInfo> &SearchList,
 372                                  unsigned First, bool Verbose) {
 373   llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenDirs;
 374   llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenFrameworkDirs;
 375   llvm::SmallPtrSet<const HeaderMap *, 8> SeenHeaderMaps;
 376   unsigned NonSystemRemoved = 0;
 377   for (unsigned i = First; i != SearchList.size(); ++i) {
 378     unsigned DirToRemove = i;
 379
 380     const DirectoryLookup &CurEntry = SearchList[i].Lookup;
 381
 382     if (CurEntry.isNormalDir()) {
 383       // If this isn't the first time we've seen this dir, remove it.
 384       if (SeenDirs.insert(CurEntry.getDir()).second)
 385         continue;
 386     } else if (CurEntry.isFramework()) {
 387       // If this isn't the first time we've seen this framework dir, remove it.
 388       if (SeenFrameworkDirs.insert(CurEntry.getFrameworkDir()).second)
 389         continue;
 390     } else {
 391       assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
 392       // If this isn't the first time we've seen this headermap, remove it.
 393       if (SeenHeaderMaps.insert(CurEntry.getHeaderMap()).second)
 394         continue;
 395     }
 396
 397     // If we have a normal #include dir/framework/headermap that is shadowed
 398     // later in the chain by a system include location, we actually want to
 399     // ignore the user's request and drop the user dir... keeping the system
 400     // dir.  This is weird, but required to emulate GCC's search path correctly.
 401     //
 402     // Since dupes of system dirs are rare, just rescan to find the original
 403     // that we're nuking instead of using a DenseMap.
 404     if (CurEntry.getDirCharacteristic() != SrcMgr::C_User) {
 405       // Find the dir that this is the same of.
 406       unsigned FirstDir;
 407       for (FirstDir = First;; ++FirstDir) {
 408         assert(FirstDir != i && "Didn't find dupe?");
 409
 410         const DirectoryLookup &SearchEntry = SearchList[FirstDir].Lookup;
 411
 412         // If these are different lookup types, then they can't be the dupe.
 413         if (SearchEntry.getLookupType() != CurEntry.getLookupType())
 414           continue;
 415
 416         bool isSame;
 417         if (CurEntry.isNormalDir())
 418           isSame = SearchEntry.getDir() == CurEntry.getDir();
 419         else if (CurEntry.isFramework())
 420           isSame = SearchEntry.getFrameworkDir() == CurEntry.getFrameworkDir();
 421         else {
 422           assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
 423           isSame = SearchEntry.getHeaderMap() == CurEntry.getHeaderMap();
 424         }
 425
 426         if (isSame)
 427           break;
 428       }
 429
 430       // If the first dir in the search path is a non-system dir, zap it
 431       // instead of the system one.
 432       if (SearchList[FirstDir].Lookup.getDirCharacteristic() == SrcMgr::C_User)
 433         DirToRemove = FirstDir;
 434     }
 435
 436     if (Verbose) {
 437       llvm::errs() << "ignoring duplicate directory \""
 438                    << CurEntry.getName() << "\"\n";
 439       if (DirToRemove != i)
 440         llvm::errs() << "  as it is a non-system directory that duplicates "
 441                      << "a system directory\n";
 442     }
 443     if (DirToRemove != i)
 444       ++NonSystemRemoved;
 445
 446     // This is reached if the current entry is a duplicate.  Remove the
 447     // DirToRemove (usually the current dir).
 448     SearchList.erase(SearchList.begin()+DirToRemove);
 449     --i;
 450   }
 451   return NonSystemRemoved;
 452 }
 453
 454 /// Extract DirectoryLookups from DirectoryLookupInfos.
 455 static std::vector<DirectoryLookup>
 456 extractLookups(const std::vector<DirectoryLookupInfo> &Infos) {
 457   std::vector<DirectoryLookup> Lookups;
 458   Lookups.reserve(Infos.size());
 459   llvm::transform(Infos, std::back_inserter(Lookups),
 460                   [](const DirectoryLookupInfo &Info) { return Info.Lookup; });
 461   return Lookups;
 462 }
 463
 464 /// Collect the mapping between indices of DirectoryLookups and UserEntries.
 465 static llvm::DenseMap<unsigned, unsigned>
 466 mapToUserEntries(const std::vector<DirectoryLookupInfo> &Infos) {
 467   llvm::DenseMap<unsigned, unsigned> LookupsToUserEntries;
 468   for (unsigned I = 0, E = Infos.size(); I < E; ++I) {
 469     // Check whether this DirectoryLookup maps to a HeaderSearch::UserEntry.
 470     if (Infos[I].UserEntryIdx)
 471       LookupsToUserEntries.insert({I, *Infos[I].UserEntryIdx});
 472   }
 473   return LookupsToUserEntries;
 474 }
 475
 476 void InitHeaderSearch::Realize(const LangOptions &Lang) {
 477   // Concatenate ANGLE+SYSTEM+AFTER chains together into SearchList.
 478   std::vector<DirectoryLookupInfo> SearchList;
 479   SearchList.reserve(IncludePath.size());
 480
 481   // Quoted arguments go first.
 482   for (auto &Include : IncludePath)
 483     if (Include.Group == Quoted)
 484       SearchList.push_back(Include);
 485
 486   // Deduplicate and remember index.
 487   RemoveDuplicates(SearchList, 0, Verbose);
 488   unsigned NumQuoted = SearchList.size();
 489
 490   for (auto &Include : IncludePath)
 491     if (Include.Group == Angled || Include.Group == IndexHeaderMap)
 492       SearchList.push_back(Include);
 493
 494   RemoveDuplicates(SearchList, NumQuoted, Verbose);
 495   unsigned NumAngled = SearchList.size();
 496
 497   for (auto &Include : IncludePath)
 498     if (Include.Group == System || Include.Group == ExternCSystem ||
 499         (!Lang.ObjC && !Lang.CPlusPlus && Include.Group == CSystem) ||
 500         (/*FIXME !Lang.ObjC && */ Lang.CPlusPlus &&
 501          Include.Group == CXXSystem) ||
 502         (Lang.ObjC && !Lang.CPlusPlus && Include.Group == ObjCSystem) ||
 503         (Lang.ObjC && Lang.CPlusPlus && Include.Group == ObjCXXSystem))
 504       SearchList.push_back(Include);
 505
 506   for (auto &Include : IncludePath)
 507     if (Include.Group == After)
 508       SearchList.push_back(Include);
 509
 510   // Remove duplicates across both the Angled and System directories.  GCC does
 511   // this and failing to remove duplicates across these two groups breaks
 512   // #include_next.
 513   unsigned NonSystemRemoved = RemoveDuplicates(SearchList, NumQuoted, Verbose);
 514   NumAngled -= NonSystemRemoved;
 515
 516   bool DontSearchCurDir = false;  // TODO: set to true if -I- is set?
 517   Headers.SetSearchPaths(extractLookups(SearchList), NumQuoted, NumAngled,
 518                          DontSearchCurDir, mapToUserEntries(SearchList));
 519
 520   Headers.SetSystemHeaderPrefixes(SystemHeaderPrefixes);
 521
 522   // If verbose, print the list of directories that will be searched.
 523   if (Verbose) {
 524     llvm::errs() << "#include \"...\" search starts here:\n";
 525     for (unsigned i = 0, e = SearchList.size(); i != e; ++i) {
 526       if (i == NumQuoted)
 527         llvm::errs() << "#include <...> search starts here:\n";
 528       StringRef Name = SearchList[i].Lookup.getName();
 529       const char *Suffix;
 530       if (SearchList[i].Lookup.isNormalDir())
 531         Suffix = "";
 532       else if (SearchList[i].Lookup.isFramework())
 533         Suffix = " (framework directory)";
 534       else {
 535         assert(SearchList[i].Lookup.isHeaderMap() && "Unknown DirectoryLookup");
 536         Suffix = " (headermap)";
 537       }
 538       llvm::errs() << " " << Name << Suffix << "\n";
 539     }
 540     llvm::errs() << "End of search list.\n";
 541   }
 542 }
 543
 544 void clang::ApplyHeaderSearchOptions(HeaderSearch &HS,
 545                                      const HeaderSearchOptions &HSOpts,
 546                                      const LangOptions &Lang,
 547                                      const llvm::Triple &Triple) {
 548   InitHeaderSearch Init(HS, HSOpts.Verbose, HSOpts.Sysroot);
 549
 550   // Add the user defined entries.
 551   for (unsigned i = 0, e = HSOpts.UserEntries.size(); i != e; ++i) {
 552     const HeaderSearchOptions::Entry &E = HSOpts.UserEntries[i];
 553     if (E.IgnoreSysRoot) {
 554       Init.AddUnmappedPath(E.Path, E.Group, E.IsFramework, i);
 555     } else {
 556       Init.AddPath(E.Path, E.Group, E.IsFramework, i);
 557     }
 558   }
 559
 560   Init.AddDefaultIncludePaths(Lang, Triple, HSOpts);
 561
 562   for (unsigned i = 0, e = HSOpts.SystemHeaderPrefixes.size(); i != e; ++i)
 563     Init.AddSystemHeaderPrefix(HSOpts.SystemHeaderPrefixes[i].Prefix,
 564                                HSOpts.SystemHeaderPrefixes[i].IsSystemHeader);
 565
 566   if (HSOpts.UseBuiltinIncludes) {
 567     // Set up the builtin include directory in the module map.
 568     SmallString<128> P = StringRef(HSOpts.ResourceDir);
 569     llvm::sys::path::append(P, "include");
 570     if (auto Dir = HS.getFileMgr().getOptionalDirectoryRef(P))
 571       HS.getModuleMap().setBuiltinIncludeDir(*Dir);
 572   }
 573
 574   Init.Realize(Lang);
 575 }