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/Basic/FileManager.h"
15 #include "clang/Basic/LangOptions.h"
16 #include "clang/Config/config.h" // C_INCLUDE_DIRS
17 #include "clang/Frontend/FrontendDiagnostic.h"
18 #include "clang/Frontend/Utils.h"
19 #include "clang/Lex/HeaderMap.h"
20 #include "clang/Lex/HeaderSearch.h"
21 #include "clang/Lex/HeaderSearchOptions.h"
22 #include "llvm/ADT/SmallPtrSet.h"
23 #include "llvm/ADT/SmallString.h"
24 #include "llvm/ADT/SmallVector.h"
25 #include "llvm/ADT/StringExtras.h"
26 #include "llvm/ADT/Triple.h"
27 #include "llvm/ADT/Twine.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include "llvm/Support/Path.h"
30 #include "llvm/Support/raw_ostream.h"
31 
32 using namespace clang;
33 using namespace clang::frontend;
34 
35 namespace {
36 
37 /// InitHeaderSearch - This class makes it easier to set the search paths of
38 ///  a HeaderSearch object. InitHeaderSearch stores several search path lists
39 ///  internally, which can be sent to a HeaderSearch object in one swoop.
40 class InitHeaderSearch {
41   std::vector<std::pair<IncludeDirGroup, DirectoryLookup> > IncludePath;
42   typedef std::vector<std::pair<IncludeDirGroup,
43                       DirectoryLookup> >::const_iterator path_iterator;
44   std::vector<std::pair<std::string, bool> > SystemHeaderPrefixes;
45   HeaderSearch &Headers;
46   bool Verbose;
47   std::string IncludeSysroot;
48   bool HasSysroot;
49 
50 public:
51 
52   InitHeaderSearch(HeaderSearch &HS, bool verbose, StringRef sysroot)
53     : Headers(HS), Verbose(verbose), IncludeSysroot(sysroot),
54       HasSysroot(!(sysroot.empty() || sysroot == "/")) {
55   }
56 
57   /// AddPath - Add the specified path to the specified group list, prefixing
58   /// the sysroot if used.
59   /// Returns true if the path exists, false if it was ignored.
60   bool AddPath(const Twine &Path, IncludeDirGroup Group, bool isFramework);
61 
62   /// AddUnmappedPath - Add the specified path to the specified group list,
63   /// without performing any sysroot remapping.
64   /// Returns true if the path exists, false if it was ignored.
65   bool AddUnmappedPath(const Twine &Path, IncludeDirGroup Group,
66                        bool isFramework);
67 
68   /// AddSystemHeaderPrefix - Add the specified prefix to the system header
69   /// prefix list.
70   void AddSystemHeaderPrefix(StringRef Prefix, bool IsSystemHeader) {
71     SystemHeaderPrefixes.emplace_back(Prefix, IsSystemHeader);
72   }
73 
74   /// AddGnuCPlusPlusIncludePaths - Add the necessary paths to support a gnu
75   ///  libstdc++.
76   /// Returns true if the \p Base path was found, false if it does not exist.
77   bool AddGnuCPlusPlusIncludePaths(StringRef Base, StringRef ArchDir,
78                                    StringRef Dir32, StringRef Dir64,
79                                    const llvm::Triple &triple);
80 
81   /// AddMinGWCPlusPlusIncludePaths - Add the necessary paths to support a MinGW
82   ///  libstdc++.
83   void AddMinGWCPlusPlusIncludePaths(StringRef Base,
84                                      StringRef Arch,
85                                      StringRef Version);
86 
87   // AddDefaultCIncludePaths - Add paths that should always be searched.
88   void AddDefaultCIncludePaths(const llvm::Triple &triple,
89                                const HeaderSearchOptions &HSOpts);
90 
91   // AddDefaultCPlusPlusIncludePaths -  Add paths that should be searched when
92   //  compiling c++.
93   void AddDefaultCPlusPlusIncludePaths(const LangOptions &LangOpts,
94                                        const llvm::Triple &triple,
95                                        const HeaderSearchOptions &HSOpts);
96 
97   /// AddDefaultSystemIncludePaths - Adds the default system include paths so
98   ///  that e.g. stdio.h is found.
99   void AddDefaultIncludePaths(const LangOptions &Lang,
100                               const llvm::Triple &triple,
101                               const HeaderSearchOptions &HSOpts);
102 
103   /// Realize - Merges all search path lists into one list and send it to
104   /// HeaderSearch.
105   void Realize(const LangOptions &Lang);
106 };
107 
108 }  // end anonymous namespace.
109 
110 static bool CanPrefixSysroot(StringRef Path) {
111 #if defined(_WIN32)
112   return !Path.empty() && llvm::sys::path::is_separator(Path[0]);
113 #else
114   return llvm::sys::path::is_absolute(Path);
115 #endif
116 }
117 
118 bool InitHeaderSearch::AddPath(const Twine &Path, IncludeDirGroup Group,
119                                bool isFramework) {
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     }
128   }
129 
130   return AddUnmappedPath(Path, Group, isFramework);
131 }
132 
133 bool InitHeaderSearch::AddUnmappedPath(const Twine &Path, IncludeDirGroup Group,
134                                        bool isFramework) {
135   assert(!Path.isTriviallyEmpty() && "can't handle empty path here");
136 
137   FileManager &FM = Headers.getFileMgr();
138   SmallString<256> MappedPathStorage;
139   StringRef MappedPathStr = Path.toStringRef(MappedPathStorage);
140 
141   // Compute the DirectoryLookup type.
142   SrcMgr::CharacteristicKind Type;
143   if (Group == Quoted || Group == Angled || Group == IndexHeaderMap) {
144     Type = SrcMgr::C_User;
145   } else if (Group == ExternCSystem) {
146     Type = SrcMgr::C_ExternCSystem;
147   } else {
148     Type = SrcMgr::C_System;
149   }
150 
151   // If the directory exists, add it.
152   if (const DirectoryEntry *DE = FM.getDirectory(MappedPathStr)) {
153     IncludePath.push_back(
154       std::make_pair(Group, DirectoryLookup(DE, Type, isFramework)));
155     return true;
156   }
157 
158   // Check to see if this is an apple-style headermap (which are not allowed to
159   // be frameworks).
160   if (!isFramework) {
161     if (const FileEntry *FE = FM.getFile(MappedPathStr)) {
162       if (const HeaderMap *HM = Headers.CreateHeaderMap(FE)) {
163         // It is a headermap, add it to the search path.
164         IncludePath.push_back(
165           std::make_pair(Group,
166                          DirectoryLookup(HM, Type, Group == IndexHeaderMap)));
167         return true;
168       }
169     }
170   }
171 
172   if (Verbose)
173     llvm::errs() << "ignoring nonexistent directory \""
174                  << MappedPathStr << "\"\n";
175   return false;
176 }
177 
178 bool InitHeaderSearch::AddGnuCPlusPlusIncludePaths(StringRef Base,
179                                                    StringRef ArchDir,
180                                                    StringRef Dir32,
181                                                    StringRef Dir64,
182                                                    const llvm::Triple &triple) {
183   // Add the base dir
184   bool IsBaseFound = AddPath(Base, CXXSystem, false);
185 
186   // Add the multilib dirs
187   llvm::Triple::ArchType arch = triple.getArch();
188   bool is64bit = arch == llvm::Triple::ppc64 || arch == llvm::Triple::x86_64;
189   if (is64bit)
190     AddPath(Base + "/" + ArchDir + "/" + Dir64, CXXSystem, false);
191   else
192     AddPath(Base + "/" + ArchDir + "/" + Dir32, CXXSystem, false);
193 
194   // Add the backward dir
195   AddPath(Base + "/backward", CXXSystem, false);
196   return IsBaseFound;
197 }
198 
199 void InitHeaderSearch::AddMinGWCPlusPlusIncludePaths(StringRef Base,
200                                                      StringRef Arch,
201                                                      StringRef Version) {
202   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++",
203           CXXSystem, false);
204   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++/" + Arch,
205           CXXSystem, false);
206   AddPath(Base + "/" + Arch + "/" + Version + "/include/c++/backward",
207           CXXSystem, false);
208 }
209 
210 void InitHeaderSearch::AddDefaultCIncludePaths(const llvm::Triple &triple,
211                                             const HeaderSearchOptions &HSOpts) {
212   llvm::Triple::OSType os = triple.getOS();
213 
214   if (HSOpts.UseStandardSystemIncludes) {
215     switch (os) {
216     case llvm::Triple::CloudABI:
217     case llvm::Triple::FreeBSD:
218     case llvm::Triple::NetBSD:
219     case llvm::Triple::OpenBSD:
220     case llvm::Triple::NaCl:
221     case llvm::Triple::PS4:
222     case llvm::Triple::ELFIAMCU:
223     case llvm::Triple::Fuchsia:
224       break;
225     case llvm::Triple::Win32:
226       if (triple.getEnvironment() != llvm::Triple::Cygnus)
227         break;
228       LLVM_FALLTHROUGH;
229     default:
230       // FIXME: temporary hack: hard-coded paths.
231       AddPath("/usr/local/include", System, false);
232       break;
233     }
234   }
235 
236   // Builtin includes use #include_next directives and should be positioned
237   // just prior C include dirs.
238   if (HSOpts.UseBuiltinIncludes) {
239     // Ignore the sys root, we *always* look for clang headers relative to
240     // supplied path.
241     SmallString<128> P = StringRef(HSOpts.ResourceDir);
242     llvm::sys::path::append(P, "include");
243     AddUnmappedPath(P, ExternCSystem, false);
244   }
245 
246   // All remaining additions are for system include directories, early exit if
247   // we aren't using them.
248   if (!HSOpts.UseStandardSystemIncludes)
249     return;
250 
251   // Add dirs specified via 'configure --with-c-include-dirs'.
252   StringRef CIncludeDirs(C_INCLUDE_DIRS);
253   if (CIncludeDirs != "") {
254     SmallVector<StringRef, 5> dirs;
255     CIncludeDirs.split(dirs, ":");
256     for (StringRef dir : dirs)
257       AddPath(dir, ExternCSystem, false);
258     return;
259   }
260 
261   switch (os) {
262   case llvm::Triple::Linux:
263   case llvm::Triple::Hurd:
264   case llvm::Triple::Solaris:
265     llvm_unreachable("Include management is handled in the driver.");
266 
267   case llvm::Triple::CloudABI: {
268     // <sysroot>/<triple>/include
269     SmallString<128> P = StringRef(HSOpts.ResourceDir);
270     llvm::sys::path::append(P, "../../..", triple.str(), "include");
271     AddPath(P, System, false);
272     break;
273   }
274 
275   case llvm::Triple::Haiku:
276     AddPath("/boot/system/non-packaged/develop/headers", System, false);
277     AddPath("/boot/system/develop/headers/os", System, false);
278     AddPath("/boot/system/develop/headers/os/app", System, false);
279     AddPath("/boot/system/develop/headers/os/arch", System, false);
280     AddPath("/boot/system/develop/headers/os/device", System, false);
281     AddPath("/boot/system/develop/headers/os/drivers", System, false);
282     AddPath("/boot/system/develop/headers/os/game", System, false);
283     AddPath("/boot/system/develop/headers/os/interface", System, false);
284     AddPath("/boot/system/develop/headers/os/kernel", System, false);
285     AddPath("/boot/system/develop/headers/os/locale", System, false);
286     AddPath("/boot/system/develop/headers/os/mail", System, false);
287     AddPath("/boot/system/develop/headers/os/media", System, false);
288     AddPath("/boot/system/develop/headers/os/midi", System, false);
289     AddPath("/boot/system/develop/headers/os/midi2", System, false);
290     AddPath("/boot/system/develop/headers/os/net", System, false);
291     AddPath("/boot/system/develop/headers/os/opengl", System, false);
292     AddPath("/boot/system/develop/headers/os/storage", System, false);
293     AddPath("/boot/system/develop/headers/os/support", System, false);
294     AddPath("/boot/system/develop/headers/os/translation", System, false);
295     AddPath("/boot/system/develop/headers/os/add-ons/graphics", System, false);
296     AddPath("/boot/system/develop/headers/os/add-ons/input_server", System, false);
297     AddPath("/boot/system/develop/headers/os/add-ons/mail_daemon", System, false);
298     AddPath("/boot/system/develop/headers/os/add-ons/registrar", System, false);
299     AddPath("/boot/system/develop/headers/os/add-ons/screen_saver", System, false);
300     AddPath("/boot/system/develop/headers/os/add-ons/tracker", System, false);
301     AddPath("/boot/system/develop/headers/os/be_apps/Deskbar", System, false);
302     AddPath("/boot/system/develop/headers/os/be_apps/NetPositive", System, false);
303     AddPath("/boot/system/develop/headers/os/be_apps/Tracker", System, false);
304     AddPath("/boot/system/develop/headers/3rdparty", System, false);
305     AddPath("/boot/system/develop/headers/bsd", System, false);
306     AddPath("/boot/system/develop/headers/glibc", System, false);
307     AddPath("/boot/system/develop/headers/posix", System, false);
308     AddPath("/boot/system/develop/headers",  System, false);
309     break;
310   case llvm::Triple::RTEMS:
311     break;
312   case llvm::Triple::Win32:
313     switch (triple.getEnvironment()) {
314     default: llvm_unreachable("Include management is handled in the driver.");
315     case llvm::Triple::Cygnus:
316       AddPath("/usr/include/w32api", System, false);
317       break;
318     case llvm::Triple::GNU:
319       break;
320     }
321     break;
322   default:
323     break;
324   }
325 
326   switch (os) {
327   case llvm::Triple::CloudABI:
328   case llvm::Triple::RTEMS:
329   case llvm::Triple::NaCl:
330   case llvm::Triple::ELFIAMCU:
331   case llvm::Triple::Fuchsia:
332     break;
333   case llvm::Triple::PS4: {
334     // <isysroot> gets prepended later in AddPath().
335     std::string BaseSDKPath = "";
336     if (!HasSysroot) {
337       const char *envValue = getenv("SCE_ORBIS_SDK_DIR");
338       if (envValue)
339         BaseSDKPath = envValue;
340       else {
341         // HSOpts.ResourceDir variable contains the location of Clang's
342         // resource files.
343         // Assuming that Clang is configured for PS4 without
344         // --with-clang-resource-dir option, the location of Clang's resource
345         // files is <SDK_DIR>/host_tools/lib/clang
346         SmallString<128> P = StringRef(HSOpts.ResourceDir);
347         llvm::sys::path::append(P, "../../..");
348         BaseSDKPath = P.str();
349       }
350     }
351     AddPath(BaseSDKPath + "/target/include", System, false);
352     if (triple.isPS4CPU())
353       AddPath(BaseSDKPath + "/target/include_common", System, false);
354     LLVM_FALLTHROUGH;
355   }
356   default:
357     AddPath("/usr/include", ExternCSystem, false);
358     break;
359   }
360 }
361 
362 void InitHeaderSearch::AddDefaultCPlusPlusIncludePaths(
363     const LangOptions &LangOpts, const llvm::Triple &triple,
364     const HeaderSearchOptions &HSOpts) {
365   llvm::Triple::OSType os = triple.getOS();
366   // FIXME: temporary hack: hard-coded paths.
367 
368   if (triple.isOSDarwin()) {
369     bool IsBaseFound = true;
370     switch (triple.getArch()) {
371     default: break;
372 
373     case llvm::Triple::ppc:
374     case llvm::Triple::ppc64:
375       IsBaseFound = AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
376                                                 "powerpc-apple-darwin10", "",
377                                                 "ppc64", triple);
378       IsBaseFound |= AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.0.0",
379                                                  "powerpc-apple-darwin10", "",
380                                                  "ppc64", triple);
381       break;
382 
383     case llvm::Triple::x86:
384     case llvm::Triple::x86_64:
385       IsBaseFound = AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
386                                                 "i686-apple-darwin10", "",
387                                                 "x86_64", triple);
388       IsBaseFound |= AddGnuCPlusPlusIncludePaths(
389           "/usr/include/c++/4.0.0", "i686-apple-darwin8", "", "", triple);
390       break;
391 
392     case llvm::Triple::arm:
393     case llvm::Triple::thumb:
394       IsBaseFound = AddGnuCPlusPlusIncludePaths(
395           "/usr/include/c++/4.2.1", "arm-apple-darwin10", "v7", "", triple);
396       IsBaseFound |= AddGnuCPlusPlusIncludePaths(
397           "/usr/include/c++/4.2.1", "arm-apple-darwin10", "v6", "", triple);
398       break;
399 
400     case llvm::Triple::aarch64:
401       IsBaseFound = AddGnuCPlusPlusIncludePaths(
402           "/usr/include/c++/4.2.1", "arm64-apple-darwin10", "", "", triple);
403       break;
404     }
405     // Warn when compiling pure C++ / Objective-C++ only.
406     if (!IsBaseFound &&
407         !(LangOpts.CUDA || LangOpts.OpenCL || LangOpts.RenderScript)) {
408       Headers.getDiags().Report(SourceLocation(),
409                                 diag::warn_stdlibcxx_not_found);
410     }
411     return;
412   }
413 
414   switch (os) {
415   case llvm::Triple::Linux:
416   case llvm::Triple::Hurd:
417   case llvm::Triple::Solaris:
418     llvm_unreachable("Include management is handled in the driver.");
419     break;
420   case llvm::Triple::Win32:
421     switch (triple.getEnvironment()) {
422     default: llvm_unreachable("Include management is handled in the driver.");
423     case llvm::Triple::Cygnus:
424       // Cygwin-1.7
425       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.7.3");
426       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.5.3");
427       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.4");
428       // g++-4 / Cygwin-1.5
429       AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.2");
430       break;
431     }
432     break;
433   case llvm::Triple::DragonFly:
434     AddPath("/usr/include/c++/5.0", CXXSystem, false);
435     break;
436   case llvm::Triple::Minix:
437     AddGnuCPlusPlusIncludePaths("/usr/gnu/include/c++/4.4.3",
438                                 "", "", "", triple);
439     break;
440   default:
441     break;
442   }
443 }
444 
445 void InitHeaderSearch::AddDefaultIncludePaths(const LangOptions &Lang,
446                                               const llvm::Triple &triple,
447                                             const HeaderSearchOptions &HSOpts) {
448   // NB: This code path is going away. All of the logic is moving into the
449   // driver which has the information necessary to do target-specific
450   // selections of default include paths. Each target which moves there will be
451   // exempted from this logic here until we can delete the entire pile of code.
452   switch (triple.getOS()) {
453   default:
454     break; // Everything else continues to use this routine's logic.
455 
456   case llvm::Triple::Linux:
457   case llvm::Triple::Hurd:
458   case llvm::Triple::Solaris:
459     return;
460 
461   case llvm::Triple::Win32:
462     if (triple.getEnvironment() != llvm::Triple::Cygnus ||
463         triple.isOSBinFormatMachO())
464       return;
465     break;
466   }
467 
468   if (Lang.CPlusPlus && !Lang.AsmPreprocessor &&
469       HSOpts.UseStandardCXXIncludes && HSOpts.UseStandardSystemIncludes) {
470     if (HSOpts.UseLibcxx) {
471       AddPath("/usr/include/c++/v1", CXXSystem, false);
472     } else {
473       AddDefaultCPlusPlusIncludePaths(Lang, triple, HSOpts);
474     }
475   }
476 
477   AddDefaultCIncludePaths(triple, HSOpts);
478 
479   // Add the default framework include paths on Darwin.
480   if (HSOpts.UseStandardSystemIncludes) {
481     if (triple.isOSDarwin()) {
482       AddPath("/System/Library/Frameworks", System, true);
483       AddPath("/Library/Frameworks", System, true);
484     }
485   }
486 }
487 
488 /// RemoveDuplicates - If there are duplicate directory entries in the specified
489 /// search list, remove the later (dead) ones.  Returns the number of non-system
490 /// headers removed, which is used to update NumAngled.
491 static unsigned RemoveDuplicates(std::vector<DirectoryLookup> &SearchList,
492                                  unsigned First, bool Verbose) {
493   llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenDirs;
494   llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenFrameworkDirs;
495   llvm::SmallPtrSet<const HeaderMap *, 8> SeenHeaderMaps;
496   unsigned NonSystemRemoved = 0;
497   for (unsigned i = First; i != SearchList.size(); ++i) {
498     unsigned DirToRemove = i;
499 
500     const DirectoryLookup &CurEntry = SearchList[i];
501 
502     if (CurEntry.isNormalDir()) {
503       // If this isn't the first time we've seen this dir, remove it.
504       if (SeenDirs.insert(CurEntry.getDir()).second)
505         continue;
506     } else if (CurEntry.isFramework()) {
507       // If this isn't the first time we've seen this framework dir, remove it.
508       if (SeenFrameworkDirs.insert(CurEntry.getFrameworkDir()).second)
509         continue;
510     } else {
511       assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
512       // If this isn't the first time we've seen this headermap, remove it.
513       if (SeenHeaderMaps.insert(CurEntry.getHeaderMap()).second)
514         continue;
515     }
516 
517     // If we have a normal #include dir/framework/headermap that is shadowed
518     // later in the chain by a system include location, we actually want to
519     // ignore the user's request and drop the user dir... keeping the system
520     // dir.  This is weird, but required to emulate GCC's search path correctly.
521     //
522     // Since dupes of system dirs are rare, just rescan to find the original
523     // that we're nuking instead of using a DenseMap.
524     if (CurEntry.getDirCharacteristic() != SrcMgr::C_User) {
525       // Find the dir that this is the same of.
526       unsigned FirstDir;
527       for (FirstDir = First;; ++FirstDir) {
528         assert(FirstDir != i && "Didn't find dupe?");
529 
530         const DirectoryLookup &SearchEntry = SearchList[FirstDir];
531 
532         // If these are different lookup types, then they can't be the dupe.
533         if (SearchEntry.getLookupType() != CurEntry.getLookupType())
534           continue;
535 
536         bool isSame;
537         if (CurEntry.isNormalDir())
538           isSame = SearchEntry.getDir() == CurEntry.getDir();
539         else if (CurEntry.isFramework())
540           isSame = SearchEntry.getFrameworkDir() == CurEntry.getFrameworkDir();
541         else {
542           assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
543           isSame = SearchEntry.getHeaderMap() == CurEntry.getHeaderMap();
544         }
545 
546         if (isSame)
547           break;
548       }
549 
550       // If the first dir in the search path is a non-system dir, zap it
551       // instead of the system one.
552       if (SearchList[FirstDir].getDirCharacteristic() == SrcMgr::C_User)
553         DirToRemove = FirstDir;
554     }
555 
556     if (Verbose) {
557       llvm::errs() << "ignoring duplicate directory \""
558                    << CurEntry.getName() << "\"\n";
559       if (DirToRemove != i)
560         llvm::errs() << "  as it is a non-system directory that duplicates "
561                      << "a system directory\n";
562     }
563     if (DirToRemove != i)
564       ++NonSystemRemoved;
565 
566     // This is reached if the current entry is a duplicate.  Remove the
567     // DirToRemove (usually the current dir).
568     SearchList.erase(SearchList.begin()+DirToRemove);
569     --i;
570   }
571   return NonSystemRemoved;
572 }
573 
574 
575 void InitHeaderSearch::Realize(const LangOptions &Lang) {
576   // Concatenate ANGLE+SYSTEM+AFTER chains together into SearchList.
577   std::vector<DirectoryLookup> SearchList;
578   SearchList.reserve(IncludePath.size());
579 
580   // Quoted arguments go first.
581   for (auto &Include : IncludePath)
582     if (Include.first == Quoted)
583       SearchList.push_back(Include.second);
584 
585   // Deduplicate and remember index.
586   RemoveDuplicates(SearchList, 0, Verbose);
587   unsigned NumQuoted = SearchList.size();
588 
589   for (auto &Include : IncludePath)
590     if (Include.first == Angled || Include.first == IndexHeaderMap)
591       SearchList.push_back(Include.second);
592 
593   RemoveDuplicates(SearchList, NumQuoted, Verbose);
594   unsigned NumAngled = SearchList.size();
595 
596   for (auto &Include : IncludePath)
597     if (Include.first == System || Include.first == ExternCSystem ||
598         (!Lang.ObjC && !Lang.CPlusPlus && Include.first == CSystem) ||
599         (/*FIXME !Lang.ObjC && */ Lang.CPlusPlus &&
600          Include.first == CXXSystem) ||
601         (Lang.ObjC && !Lang.CPlusPlus && Include.first == ObjCSystem) ||
602         (Lang.ObjC && Lang.CPlusPlus && Include.first == ObjCXXSystem))
603       SearchList.push_back(Include.second);
604 
605   for (auto &Include : IncludePath)
606     if (Include.first == After)
607       SearchList.push_back(Include.second);
608 
609   // Remove duplicates across both the Angled and System directories.  GCC does
610   // this and failing to remove duplicates across these two groups breaks
611   // #include_next.
612   unsigned NonSystemRemoved = RemoveDuplicates(SearchList, NumQuoted, Verbose);
613   NumAngled -= NonSystemRemoved;
614 
615   bool DontSearchCurDir = false;  // TODO: set to true if -I- is set?
616   Headers.SetSearchPaths(SearchList, NumQuoted, NumAngled, DontSearchCurDir);
617 
618   Headers.SetSystemHeaderPrefixes(SystemHeaderPrefixes);
619 
620   // If verbose, print the list of directories that will be searched.
621   if (Verbose) {
622     llvm::errs() << "#include \"...\" search starts here:\n";
623     for (unsigned i = 0, e = SearchList.size(); i != e; ++i) {
624       if (i == NumQuoted)
625         llvm::errs() << "#include <...> search starts here:\n";
626       StringRef Name = SearchList[i].getName();
627       const char *Suffix;
628       if (SearchList[i].isNormalDir())
629         Suffix = "";
630       else if (SearchList[i].isFramework())
631         Suffix = " (framework directory)";
632       else {
633         assert(SearchList[i].isHeaderMap() && "Unknown DirectoryLookup");
634         Suffix = " (headermap)";
635       }
636       llvm::errs() << " " << Name << Suffix << "\n";
637     }
638     llvm::errs() << "End of search list.\n";
639   }
640 }
641 
642 void clang::ApplyHeaderSearchOptions(HeaderSearch &HS,
643                                      const HeaderSearchOptions &HSOpts,
644                                      const LangOptions &Lang,
645                                      const llvm::Triple &Triple) {
646   InitHeaderSearch Init(HS, HSOpts.Verbose, HSOpts.Sysroot);
647 
648   // Add the user defined entries.
649   for (unsigned i = 0, e = HSOpts.UserEntries.size(); i != e; ++i) {
650     const HeaderSearchOptions::Entry &E = HSOpts.UserEntries[i];
651     if (E.IgnoreSysRoot) {
652       Init.AddUnmappedPath(E.Path, E.Group, E.IsFramework);
653     } else {
654       Init.AddPath(E.Path, E.Group, E.IsFramework);
655     }
656   }
657 
658   Init.AddDefaultIncludePaths(Lang, Triple, HSOpts);
659 
660   for (unsigned i = 0, e = HSOpts.SystemHeaderPrefixes.size(); i != e; ++i)
661     Init.AddSystemHeaderPrefix(HSOpts.SystemHeaderPrefixes[i].Prefix,
662                                HSOpts.SystemHeaderPrefixes[i].IsSystemHeader);
663 
664   if (HSOpts.UseBuiltinIncludes) {
665     // Set up the builtin include directory in the module map.
666     SmallString<128> P = StringRef(HSOpts.ResourceDir);
667     llvm::sys::path::append(P, "include");
668     if (const DirectoryEntry *Dir = HS.getFileMgr().getDirectory(P))
669       HS.getModuleMap().setBuiltinIncludeDir(Dir);
670   }
671 
672   Init.Realize(Lang);
673 }
674