Home | History | Annotate | Download | only in Frontend
      1 //===--- InitHeaderSearch.cpp - Initialize header search paths ------------===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This file implements the InitHeaderSearch class.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #include "clang/Frontend/Utils.h"
     15 #include "clang/Basic/FileManager.h"
     16 #include "clang/Basic/LangOptions.h"
     17 #include "clang/Config/config.h" // C_INCLUDE_DIRS
     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/Triple.h"
     25 #include "llvm/ADT/Twine.h"
     26 #include "llvm/Support/ErrorHandling.h"
     27 #include "llvm/Support/FileSystem.h"
     28 #include "llvm/Support/Path.h"
     29 #include "llvm/Support/raw_ostream.h"
     30 
     31 using namespace clang;
     32 using namespace clang::frontend;
     33 
     34 namespace {
     35 
     36 /// InitHeaderSearch - This class makes it easier to set the search paths of
     37 ///  a HeaderSearch object. InitHeaderSearch stores several search path lists
     38 ///  internally, which can be sent to a HeaderSearch object in one swoop.
     39 class InitHeaderSearch {
     40   std::vector<std::pair<IncludeDirGroup, DirectoryLookup> > IncludePath;
     41   typedef std::vector<std::pair<IncludeDirGroup,
     42                       DirectoryLookup> >::const_iterator path_iterator;
     43   std::vector<std::pair<std::string, bool> > SystemHeaderPrefixes;
     44   HeaderSearch &Headers;
     45   bool Verbose;
     46   std::string IncludeSysroot;
     47   bool HasSysroot;
     48 
     49 public:
     50 
     51   InitHeaderSearch(HeaderSearch &HS, bool verbose, StringRef sysroot)
     52     : Headers(HS), Verbose(verbose), IncludeSysroot(sysroot),
     53       HasSysroot(!(sysroot.empty() || sysroot == "/")) {
     54   }
     55 
     56   /// AddPath - Add the specified path to the specified group list, prefixing
     57   /// the sysroot if used.
     58   void AddPath(const Twine &Path, IncludeDirGroup Group, bool isFramework);
     59 
     60   /// AddUnmappedPath - Add the specified path to the specified group list,
     61   /// without performing any sysroot remapping.
     62   void AddUnmappedPath(const Twine &Path, IncludeDirGroup Group,
     63                        bool isFramework);
     64 
     65   /// AddSystemHeaderPrefix - Add the specified prefix to the system header
     66   /// prefix list.
     67   void AddSystemHeaderPrefix(StringRef Prefix, bool IsSystemHeader) {
     68     SystemHeaderPrefixes.push_back(std::make_pair(Prefix, IsSystemHeader));
     69   }
     70 
     71   /// AddGnuCPlusPlusIncludePaths - Add the necessary paths to support a gnu
     72   ///  libstdc++.
     73   void AddGnuCPlusPlusIncludePaths(StringRef Base,
     74                                    StringRef ArchDir,
     75                                    StringRef Dir32,
     76                                    StringRef Dir64,
     77                                    const llvm::Triple &triple);
     78 
     79   /// AddMinGWCPlusPlusIncludePaths - Add the necessary paths to support a MinGW
     80   ///  libstdc++.
     81   void AddMinGWCPlusPlusIncludePaths(StringRef Base,
     82                                      StringRef Arch,
     83                                      StringRef Version);
     84 
     85   /// AddMinGW64CXXPaths - Add the necessary paths to support
     86   /// libstdc++ of x86_64-w64-mingw32 aka mingw-w64.
     87   void AddMinGW64CXXPaths(StringRef Base,
     88                           StringRef Version);
     89 
     90   // AddDefaultCIncludePaths - Add paths that should always be searched.
     91   void AddDefaultCIncludePaths(const llvm::Triple &triple,
     92                                const HeaderSearchOptions &HSOpts);
     93 
     94   // AddDefaultCPlusPlusIncludePaths -  Add paths that should be searched when
     95   //  compiling c++.
     96   void AddDefaultCPlusPlusIncludePaths(const llvm::Triple &triple,
     97                                        const HeaderSearchOptions &HSOpts);
     98 
     99   /// AddDefaultSystemIncludePaths - Adds the default system include paths so
    100   ///  that e.g. stdio.h is found.
    101   void AddDefaultIncludePaths(const LangOptions &Lang,
    102                               const llvm::Triple &triple,
    103                               const HeaderSearchOptions &HSOpts);
    104 
    105   /// Realize - Merges all search path lists into one list and send it to
    106   /// HeaderSearch.
    107   void Realize(const LangOptions &Lang);
    108 };
    109 
    110 }  // end anonymous namespace.
    111 
    112 static bool CanPrefixSysroot(StringRef Path) {
    113 #if defined(_WIN32)
    114   return !Path.empty() && llvm::sys::path::is_separator(Path[0]);
    115 #else
    116   return llvm::sys::path::is_absolute(Path);
    117 #endif
    118 }
    119 
    120 void InitHeaderSearch::AddPath(const Twine &Path, IncludeDirGroup Group,
    121                                bool isFramework) {
    122   // Add the path with sysroot prepended, if desired and this is a system header
    123   // group.
    124   if (HasSysroot) {
    125     SmallString<256> MappedPathStorage;
    126     StringRef MappedPathStr = Path.toStringRef(MappedPathStorage);
    127     if (CanPrefixSysroot(MappedPathStr)) {
    128       AddUnmappedPath(IncludeSysroot + Path, Group, isFramework);
    129       return;
    130     }
    131   }
    132 
    133   AddUnmappedPath(Path, Group, isFramework);
    134 }
    135 
    136 void InitHeaderSearch::AddUnmappedPath(const Twine &Path, IncludeDirGroup Group,
    137                                        bool isFramework) {
    138   assert(!Path.isTriviallyEmpty() && "can't handle empty path here");
    139 
    140   FileManager &FM = Headers.getFileMgr();
    141   SmallString<256> MappedPathStorage;
    142   StringRef MappedPathStr = Path.toStringRef(MappedPathStorage);
    143 
    144   // Compute the DirectoryLookup type.
    145   SrcMgr::CharacteristicKind Type;
    146   if (Group == Quoted || Group == Angled || Group == IndexHeaderMap) {
    147     Type = SrcMgr::C_User;
    148   } else if (Group == ExternCSystem) {
    149     Type = SrcMgr::C_ExternCSystem;
    150   } else {
    151     Type = SrcMgr::C_System;
    152   }
    153 
    154   // If the directory exists, add it.
    155   if (const DirectoryEntry *DE = FM.getDirectory(MappedPathStr)) {
    156     IncludePath.push_back(
    157       std::make_pair(Group, DirectoryLookup(DE, Type, isFramework)));
    158     return;
    159   }
    160 
    161   // Check to see if this is an apple-style headermap (which are not allowed to
    162   // be frameworks).
    163   if (!isFramework) {
    164     if (const FileEntry *FE = FM.getFile(MappedPathStr)) {
    165       if (const HeaderMap *HM = Headers.CreateHeaderMap(FE)) {
    166         // It is a headermap, add it to the search path.
    167         IncludePath.push_back(
    168           std::make_pair(Group,
    169                          DirectoryLookup(HM, Type, Group == IndexHeaderMap)));
    170         return;
    171       }
    172     }
    173   }
    174 
    175   if (Verbose)
    176     llvm::errs() << "ignoring nonexistent directory \""
    177                  << MappedPathStr << "\"\n";
    178 }
    179 
    180 void InitHeaderSearch::AddGnuCPlusPlusIncludePaths(StringRef Base,
    181                                                    StringRef ArchDir,
    182                                                    StringRef Dir32,
    183                                                    StringRef Dir64,
    184                                                    const llvm::Triple &triple) {
    185   // Add the base dir
    186   AddPath(Base, CXXSystem, false);
    187 
    188   // Add the multilib dirs
    189   llvm::Triple::ArchType arch = triple.getArch();
    190   bool is64bit = arch == llvm::Triple::ppc64 || arch == llvm::Triple::x86_64;
    191   if (is64bit)
    192     AddPath(Base + "/" + ArchDir + "/" + Dir64, CXXSystem, false);
    193   else
    194     AddPath(Base + "/" + ArchDir + "/" + Dir32, CXXSystem, false);
    195 
    196   // Add the backward dir
    197   AddPath(Base + "/backward", CXXSystem, false);
    198 }
    199 
    200 void InitHeaderSearch::AddMinGWCPlusPlusIncludePaths(StringRef Base,
    201                                                      StringRef Arch,
    202                                                      StringRef Version) {
    203   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++",
    204           CXXSystem, false);
    205   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++/" + Arch,
    206           CXXSystem, false);
    207   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++/backward",
    208           CXXSystem, false);
    209 }
    210 
    211 void InitHeaderSearch::AddMinGW64CXXPaths(StringRef Base,
    212                                           StringRef Version) {
    213   // Assumes Base is HeaderSearchOpts' ResourceDir
    214   AddPath(Base + "/../../../include/c++/" + Version,
    215           CXXSystem, false);
    216   AddPath(Base + "/../../../include/c++/" + Version + "/x86_64-w64-mingw32",
    217           CXXSystem, false);
    218   AddPath(Base + "/../../../include/c++/" + Version + "/i686-w64-mingw32",
    219           CXXSystem, false);
    220   AddPath(Base + "/../../../include/c++/" + Version + "/backward",
    221           CXXSystem, false);
    222 }
    223 
    224 void InitHeaderSearch::AddDefaultCIncludePaths(const llvm::Triple &triple,
    225                                             const HeaderSearchOptions &HSOpts) {
    226   llvm::Triple::OSType os = triple.getOS();
    227 
    228   if (HSOpts.UseStandardSystemIncludes) {
    229     switch (os) {
    230     case llvm::Triple::FreeBSD:
    231     case llvm::Triple::NetBSD:
    232     case llvm::Triple::OpenBSD:
    233     case llvm::Triple::Bitrig:
    234       break;
    235     default:
    236       // FIXME: temporary hack: hard-coded paths.
    237       AddPath("/usr/local/include", System, false);
    238       break;
    239     }
    240   }
    241 
    242   // Builtin includes use #include_next directives and should be positioned
    243   // just prior C include dirs.
    244   if (HSOpts.UseBuiltinIncludes) {
    245     // Ignore the sys root, we *always* look for clang headers relative to
    246     // supplied path.
    247     SmallString<128> P = StringRef(HSOpts.ResourceDir);
    248     llvm::sys::path::append(P, "include");
    249     AddUnmappedPath(P.str(), ExternCSystem, false);
    250   }
    251 
    252   // All remaining additions are for system include directories, early exit if
    253   // we aren't using them.
    254   if (!HSOpts.UseStandardSystemIncludes)
    255     return;
    256 
    257   // Add dirs specified via 'configure --with-c-include-dirs'.
    258   StringRef CIncludeDirs(C_INCLUDE_DIRS);
    259   if (CIncludeDirs != "") {
    260     SmallVector<StringRef, 5> dirs;
    261     CIncludeDirs.split(dirs, ":");
    262     for (SmallVectorImpl<StringRef>::iterator i = dirs.begin();
    263          i != dirs.end();
    264          ++i)
    265       AddPath(*i, ExternCSystem, false);
    266     return;
    267   }
    268 
    269   switch (os) {
    270   case llvm::Triple::Linux:
    271   case llvm::Triple::Win32:
    272     llvm_unreachable("Include management is handled in the driver.");
    273 
    274   case llvm::Triple::Haiku:
    275     AddPath("/boot/common/include", System, false);
    276     AddPath("/boot/develop/headers/os", System, false);
    277     AddPath("/boot/develop/headers/os/app", System, false);
    278     AddPath("/boot/develop/headers/os/arch", System, false);
    279     AddPath("/boot/develop/headers/os/device", System, false);
    280     AddPath("/boot/develop/headers/os/drivers", System, false);
    281     AddPath("/boot/develop/headers/os/game", System, false);
    282     AddPath("/boot/develop/headers/os/interface", System, false);
    283     AddPath("/boot/develop/headers/os/kernel", System, false);
    284     AddPath("/boot/develop/headers/os/locale", System, false);
    285     AddPath("/boot/develop/headers/os/mail", System, false);
    286     AddPath("/boot/develop/headers/os/media", System, false);
    287     AddPath("/boot/develop/headers/os/midi", System, false);
    288     AddPath("/boot/develop/headers/os/midi2", System, false);
    289     AddPath("/boot/develop/headers/os/net", System, false);
    290     AddPath("/boot/develop/headers/os/storage", System, false);
    291     AddPath("/boot/develop/headers/os/support", System, false);
    292     AddPath("/boot/develop/headers/os/translation", System, false);
    293     AddPath("/boot/develop/headers/os/add-ons/graphics", System, false);
    294     AddPath("/boot/develop/headers/os/add-ons/input_server", System, false);
    295     AddPath("/boot/develop/headers/os/add-ons/screen_saver", System, false);
    296     AddPath("/boot/develop/headers/os/add-ons/tracker", System, false);
    297     AddPath("/boot/develop/headers/os/be_apps/Deskbar", System, false);
    298     AddPath("/boot/develop/headers/os/be_apps/NetPositive", System, false);
    299     AddPath("/boot/develop/headers/os/be_apps/Tracker", System, false);
    300     AddPath("/boot/develop/headers/cpp", System, false);
    301     AddPath("/boot/develop/headers/cpp/i586-pc-haiku", System, false);
    302     AddPath("/boot/develop/headers/3rdparty", System, false);
    303     AddPath("/boot/develop/headers/bsd", System, false);
    304     AddPath("/boot/develop/headers/glibc", System, false);
    305     AddPath("/boot/develop/headers/posix", System, false);
    306     AddPath("/boot/develop/headers",  System, false);
    307     break;
    308   case llvm::Triple::RTEMS:
    309     break;
    310   case llvm::Triple::Cygwin:
    311     AddPath("/usr/include/w32api", System, false);
    312     break;
    313   case llvm::Triple::MinGW32: {
    314       // mingw-w64 crt include paths
    315       // <sysroot>/i686-w64-mingw32/include
    316       SmallString<128> P = StringRef(HSOpts.ResourceDir);
    317       llvm::sys::path::append(P, "../../../i686-w64-mingw32/include");
    318       AddPath(P.str(), System, false);
    319 
    320       // <sysroot>/x86_64-w64-mingw32/include
    321       P.resize(HSOpts.ResourceDir.size());
    322       llvm::sys::path::append(P, "../../../x86_64-w64-mingw32/include");
    323       AddPath(P.str(), System, false);
    324 
    325       // mingw.org crt include paths
    326       // <sysroot>/include
    327       P.resize(HSOpts.ResourceDir.size());
    328       llvm::sys::path::append(P, "../../../include");
    329       AddPath(P.str(), System, false);
    330       AddPath("/mingw/include", System, false);
    331 #if defined(_WIN32)
    332       AddPath("c:/mingw/include", System, false);
    333 #endif
    334     }
    335     break;
    336 
    337   default:
    338     break;
    339   }
    340 
    341   if ( os != llvm::Triple::RTEMS )
    342     AddPath("/usr/include", ExternCSystem, false);
    343 }
    344 
    345 void InitHeaderSearch::
    346 AddDefaultCPlusPlusIncludePaths(const llvm::Triple &triple, const HeaderSearchOptions &HSOpts) {
    347   llvm::Triple::OSType os = triple.getOS();
    348   // FIXME: temporary hack: hard-coded paths.
    349 
    350   if (triple.isOSDarwin()) {
    351     switch (triple.getArch()) {
    352     default: break;
    353 
    354     case llvm::Triple::ppc:
    355     case llvm::Triple::ppc64:
    356       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
    357                                   "powerpc-apple-darwin10", "", "ppc64",
    358                                   triple);
    359       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.0.0",
    360                                   "powerpc-apple-darwin10", "", "ppc64",
    361                                   triple);
    362       break;
    363 
    364     case llvm::Triple::x86:
    365     case llvm::Triple::x86_64:
    366       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
    367                                   "i686-apple-darwin10", "", "x86_64", triple);
    368       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.0.0",
    369                                   "i686-apple-darwin8", "", "", triple);
    370       break;
    371 
    372     case llvm::Triple::arm:
    373     case llvm::Triple::thumb:
    374       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
    375                                   "arm-apple-darwin10", "v7", "", triple);
    376       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
    377                                   "arm-apple-darwin10", "v6", "", triple);
    378       break;
    379     }
    380     return;
    381   }
    382 
    383   switch (os) {
    384   case llvm::Triple::Linux:
    385   case llvm::Triple::Win32:
    386     llvm_unreachable("Include management is handled in the driver.");
    387 
    388   case llvm::Triple::Cygwin:
    389     // Cygwin-1.7
    390     AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.5.3");
    391     AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.4");
    392     // g++-4 / Cygwin-1.5
    393     AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.2");
    394     break;
    395   case llvm::Triple::MinGW32:
    396     // mingw-w64 C++ include paths (i686-w64-mingw32 and x86_64-w64-mingw32)
    397     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.0");
    398     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.1");
    399     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.2");
    400     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.3");
    401     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.4");
    402     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.0");
    403     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.1");
    404     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.2");
    405     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.3");
    406     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.7.0");
    407     // mingw.org C++ include paths
    408     AddMinGWCPlusPlusIncludePaths("/mingw/lib/gcc", "mingw32", "4.5.2"); //MSYS
    409 #if defined(_WIN32)
    410     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.6.2");
    411     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.6.1");
    412     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.5.2");
    413     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.5.0");
    414     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.4.0");
    415     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.3.0");
    416 #endif
    417     break;
    418   case llvm::Triple::DragonFly:
    419     if (llvm::sys::fs::exists("/usr/lib/gcc47"))
    420       AddPath("/usr/include/c++/4.7", CXXSystem, false);
    421     else
    422       AddPath("/usr/include/c++/4.4", CXXSystem, false);
    423     break;
    424   case llvm::Triple::FreeBSD:
    425     // FreeBSD 8.0
    426     // FreeBSD 7.3
    427     AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2", "", "", "", triple);
    428     break;
    429   case llvm::Triple::OpenBSD: {
    430     std::string t = triple.getTriple();
    431     if (t.substr(0, 6) == "x86_64")
    432       t.replace(0, 6, "amd64");
    433     AddGnuCPlusPlusIncludePaths("/usr/include/g++",
    434                                 t, "", "", triple);
    435     break;
    436   }
    437   case llvm::Triple::Minix:
    438     AddGnuCPlusPlusIncludePaths("/usr/gnu/include/c++/4.4.3",
    439                                 "", "", "", triple);
    440     break;
    441   case llvm::Triple::Solaris:
    442     AddGnuCPlusPlusIncludePaths("/usr/gcc/4.5/include/c++/4.5.2/",
    443                                 "i386-pc-solaris2.11", "", "", triple);
    444     // Solaris - Fall though..
    445   case llvm::Triple::AuroraUX:
    446     // AuroraUX
    447     AddGnuCPlusPlusIncludePaths("/opt/gcc4/include/c++/4.2.4",
    448                                 "i386-pc-solaris2.11", "", "", triple);
    449     break;
    450   default:
    451     break;
    452   }
    453 }
    454 
    455 void InitHeaderSearch::AddDefaultIncludePaths(const LangOptions &Lang,
    456                                               const llvm::Triple &triple,
    457                                             const HeaderSearchOptions &HSOpts) {
    458   // NB: This code path is going away. All of the logic is moving into the
    459   // driver which has the information necessary to do target-specific
    460   // selections of default include paths. Each target which moves there will be
    461   // exempted from this logic here until we can delete the entire pile of code.
    462   switch (triple.getOS()) {
    463   default:
    464     break; // Everything else continues to use this routine's logic.
    465 
    466   case llvm::Triple::Linux:
    467   case llvm::Triple::Win32:
    468     return;
    469   }
    470 
    471   if (Lang.CPlusPlus && HSOpts.UseStandardCXXIncludes &&
    472       HSOpts.UseStandardSystemIncludes) {
    473     if (HSOpts.UseLibcxx) {
    474       if (triple.isOSDarwin()) {
    475         // On Darwin, libc++ may be installed alongside the compiler in
    476         // lib/c++/v1.
    477         if (!HSOpts.ResourceDir.empty()) {
    478           // Remove version from foo/lib/clang/version
    479           StringRef NoVer = llvm::sys::path::parent_path(HSOpts.ResourceDir);
    480           // Remove clang from foo/lib/clang
    481           SmallString<128> P = llvm::sys::path::parent_path(NoVer);
    482 
    483           // Get foo/lib/c++/v1
    484           llvm::sys::path::append(P, "c++", "v1");
    485           AddUnmappedPath(P.str(), CXXSystem, false);
    486         }
    487       }
    488       // On Solaris, include the support directory for things like xlocale and
    489       // fudged system headers.
    490       if (triple.getOS() == llvm::Triple::Solaris)
    491         AddPath("/usr/include/c++/v1/support/solaris", CXXSystem, false);
    492 
    493       AddPath("/usr/include/c++/v1", CXXSystem, false);
    494     } else {
    495       AddDefaultCPlusPlusIncludePaths(triple, HSOpts);
    496     }
    497   }
    498 
    499   AddDefaultCIncludePaths(triple, HSOpts);
    500 
    501   // Add the default framework include paths on Darwin.
    502   if (HSOpts.UseStandardSystemIncludes) {
    503     if (triple.isOSDarwin()) {
    504       AddPath("/System/Library/Frameworks", System, true);
    505       AddPath("/Library/Frameworks", System, true);
    506     }
    507   }
    508 }
    509 
    510 /// RemoveDuplicates - If there are duplicate directory entries in the specified
    511 /// search list, remove the later (dead) ones.  Returns the number of non-system
    512 /// headers removed, which is used to update NumAngled.
    513 static unsigned RemoveDuplicates(std::vector<DirectoryLookup> &SearchList,
    514                                  unsigned First, bool Verbose) {
    515   llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenDirs;
    516   llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenFrameworkDirs;
    517   llvm::SmallPtrSet<const HeaderMap *, 8> SeenHeaderMaps;
    518   unsigned NonSystemRemoved = 0;
    519   for (unsigned i = First; i != SearchList.size(); ++i) {
    520     unsigned DirToRemove = i;
    521 
    522     const DirectoryLookup &CurEntry = SearchList[i];
    523 
    524     if (CurEntry.isNormalDir()) {
    525       // If this isn't the first time we've seen this dir, remove it.
    526       if (SeenDirs.insert(CurEntry.getDir()))
    527         continue;
    528     } else if (CurEntry.isFramework()) {
    529       // If this isn't the first time we've seen this framework dir, remove it.
    530       if (SeenFrameworkDirs.insert(CurEntry.getFrameworkDir()))
    531         continue;
    532     } else {
    533       assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
    534       // If this isn't the first time we've seen this headermap, remove it.
    535       if (SeenHeaderMaps.insert(CurEntry.getHeaderMap()))
    536         continue;
    537     }
    538 
    539     // If we have a normal #include dir/framework/headermap that is shadowed
    540     // later in the chain by a system include location, we actually want to
    541     // ignore the user's request and drop the user dir... keeping the system
    542     // dir.  This is weird, but required to emulate GCC's search path correctly.
    543     //
    544     // Since dupes of system dirs are rare, just rescan to find the original
    545     // that we're nuking instead of using a DenseMap.
    546     if (CurEntry.getDirCharacteristic() != SrcMgr::C_User) {
    547       // Find the dir that this is the same of.
    548       unsigned FirstDir;
    549       for (FirstDir = 0; ; ++FirstDir) {
    550         assert(FirstDir != i && "Didn't find dupe?");
    551 
    552         const DirectoryLookup &SearchEntry = SearchList[FirstDir];
    553 
    554         // If these are different lookup types, then they can't be the dupe.
    555         if (SearchEntry.getLookupType() != CurEntry.getLookupType())
    556           continue;
    557 
    558         bool isSame;
    559         if (CurEntry.isNormalDir())
    560           isSame = SearchEntry.getDir() == CurEntry.getDir();
    561         else if (CurEntry.isFramework())
    562           isSame = SearchEntry.getFrameworkDir() == CurEntry.getFrameworkDir();
    563         else {
    564           assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
    565           isSame = SearchEntry.getHeaderMap() == CurEntry.getHeaderMap();
    566         }
    567 
    568         if (isSame)
    569           break;
    570       }
    571 
    572       // If the first dir in the search path is a non-system dir, zap it
    573       // instead of the system one.
    574       if (SearchList[FirstDir].getDirCharacteristic() == SrcMgr::C_User)
    575         DirToRemove = FirstDir;
    576     }
    577 
    578     if (Verbose) {
    579       llvm::errs() << "ignoring duplicate directory \""
    580                    << CurEntry.getName() << "\"\n";
    581       if (DirToRemove != i)
    582         llvm::errs() << "  as it is a non-system directory that duplicates "
    583                      << "a system directory\n";
    584     }
    585     if (DirToRemove != i)
    586       ++NonSystemRemoved;
    587 
    588     // This is reached if the current entry is a duplicate.  Remove the
    589     // DirToRemove (usually the current dir).
    590     SearchList.erase(SearchList.begin()+DirToRemove);
    591     --i;
    592   }
    593   return NonSystemRemoved;
    594 }
    595 
    596 
    597 void InitHeaderSearch::Realize(const LangOptions &Lang) {
    598   // Concatenate ANGLE+SYSTEM+AFTER chains together into SearchList.
    599   std::vector<DirectoryLookup> SearchList;
    600   SearchList.reserve(IncludePath.size());
    601 
    602   // Quoted arguments go first.
    603   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
    604        it != ie; ++it) {
    605     if (it->first == Quoted)
    606       SearchList.push_back(it->second);
    607   }
    608   // Deduplicate and remember index.
    609   RemoveDuplicates(SearchList, 0, Verbose);
    610   unsigned NumQuoted = SearchList.size();
    611 
    612   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
    613        it != ie; ++it) {
    614     if (it->first == Angled || it->first == IndexHeaderMap)
    615       SearchList.push_back(it->second);
    616   }
    617 
    618   RemoveDuplicates(SearchList, NumQuoted, Verbose);
    619   unsigned NumAngled = SearchList.size();
    620 
    621   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
    622        it != ie; ++it) {
    623     if (it->first == System || it->first == ExternCSystem ||
    624         (!Lang.ObjC1 && !Lang.CPlusPlus && it->first == CSystem)    ||
    625         (/*FIXME !Lang.ObjC1 && */Lang.CPlusPlus  && it->first == CXXSystem)  ||
    626         (Lang.ObjC1  && !Lang.CPlusPlus && it->first == ObjCSystem) ||
    627         (Lang.ObjC1  && Lang.CPlusPlus  && it->first == ObjCXXSystem))
    628       SearchList.push_back(it->second);
    629   }
    630 
    631   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
    632        it != ie; ++it) {
    633     if (it->first == After)
    634       SearchList.push_back(it->second);
    635   }
    636 
    637   // Remove duplicates across both the Angled and System directories.  GCC does
    638   // this and failing to remove duplicates across these two groups breaks
    639   // #include_next.
    640   unsigned NonSystemRemoved = RemoveDuplicates(SearchList, NumQuoted, Verbose);
    641   NumAngled -= NonSystemRemoved;
    642 
    643   bool DontSearchCurDir = false;  // TODO: set to true if -I- is set?
    644   Headers.SetSearchPaths(SearchList, NumQuoted, NumAngled, DontSearchCurDir);
    645 
    646   Headers.SetSystemHeaderPrefixes(SystemHeaderPrefixes);
    647 
    648   // If verbose, print the list of directories that will be searched.
    649   if (Verbose) {
    650     llvm::errs() << "#include \"...\" search starts here:\n";
    651     for (unsigned i = 0, e = SearchList.size(); i != e; ++i) {
    652       if (i == NumQuoted)
    653         llvm::errs() << "#include <...> search starts here:\n";
    654       const char *Name = SearchList[i].getName();
    655       const char *Suffix;
    656       if (SearchList[i].isNormalDir())
    657         Suffix = "";
    658       else if (SearchList[i].isFramework())
    659         Suffix = " (framework directory)";
    660       else {
    661         assert(SearchList[i].isHeaderMap() && "Unknown DirectoryLookup");
    662         Suffix = " (headermap)";
    663       }
    664       llvm::errs() << " " << Name << Suffix << "\n";
    665     }
    666     llvm::errs() << "End of search list.\n";
    667   }
    668 }
    669 
    670 void clang::ApplyHeaderSearchOptions(HeaderSearch &HS,
    671                                      const HeaderSearchOptions &HSOpts,
    672                                      const LangOptions &Lang,
    673                                      const llvm::Triple &Triple) {
    674   InitHeaderSearch Init(HS, HSOpts.Verbose, HSOpts.Sysroot);
    675 
    676   // Add the user defined entries.
    677   for (unsigned i = 0, e = HSOpts.UserEntries.size(); i != e; ++i) {
    678     const HeaderSearchOptions::Entry &E = HSOpts.UserEntries[i];
    679     if (E.IgnoreSysRoot) {
    680       Init.AddUnmappedPath(E.Path, E.Group, E.IsFramework);
    681     } else {
    682       Init.AddPath(E.Path, E.Group, E.IsFramework);
    683     }
    684   }
    685 
    686   Init.AddDefaultIncludePaths(Lang, Triple, HSOpts);
    687 
    688   for (unsigned i = 0, e = HSOpts.SystemHeaderPrefixes.size(); i != e; ++i)
    689     Init.AddSystemHeaderPrefix(HSOpts.SystemHeaderPrefixes[i].Prefix,
    690                                HSOpts.SystemHeaderPrefixes[i].IsSystemHeader);
    691 
    692   if (HSOpts.UseBuiltinIncludes) {
    693     // Set up the builtin include directory in the module map.
    694     SmallString<128> P = StringRef(HSOpts.ResourceDir);
    695     llvm::sys::path::append(P, "include");
    696     if (const DirectoryEntry *Dir = HS.getFileMgr().getDirectory(P.str()))
    697       HS.getModuleMap().setBuiltinIncludeDir(Dir);
    698   }
    699 
    700   Init.Realize(Lang);
    701 }
    702