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::Minix:
234     case llvm::Triple::Bitrig:
235       break;
236     default:
237       // FIXME: temporary hack: hard-coded paths.
238       AddPath("/usr/local/include", System, false);
239       break;
240     }
241   }
242 
243   // Builtin includes use #include_next directives and should be positioned
244   // just prior C include dirs.
245   if (HSOpts.UseBuiltinIncludes) {
246     // Ignore the sys root, we *always* look for clang headers relative to
247     // supplied path.
248     SmallString<128> P = StringRef(HSOpts.ResourceDir);
249     llvm::sys::path::append(P, "include");
250     AddUnmappedPath(P.str(), ExternCSystem, false);
251   }
252 
253   // All remaining additions are for system include directories, early exit if
254   // we aren't using them.
255   if (!HSOpts.UseStandardSystemIncludes)
256     return;
257 
258   // Add dirs specified via 'configure --with-c-include-dirs'.
259   StringRef CIncludeDirs(C_INCLUDE_DIRS);
260   if (CIncludeDirs != "") {
261     SmallVector<StringRef, 5> dirs;
262     CIncludeDirs.split(dirs, ":");
263     for (SmallVectorImpl<StringRef>::iterator i = dirs.begin();
264          i != dirs.end();
265          ++i)
266       AddPath(*i, ExternCSystem, false);
267     return;
268   }
269 
270   switch (os) {
271   case llvm::Triple::Linux:
272   case llvm::Triple::Win32:
273     llvm_unreachable("Include management is handled in the driver.");
274 
275   case llvm::Triple::Haiku:
276     AddPath("/boot/common/include", System, false);
277     AddPath("/boot/develop/headers/os", System, false);
278     AddPath("/boot/develop/headers/os/app", System, false);
279     AddPath("/boot/develop/headers/os/arch", System, false);
280     AddPath("/boot/develop/headers/os/device", System, false);
281     AddPath("/boot/develop/headers/os/drivers", System, false);
282     AddPath("/boot/develop/headers/os/game", System, false);
283     AddPath("/boot/develop/headers/os/interface", System, false);
284     AddPath("/boot/develop/headers/os/kernel", System, false);
285     AddPath("/boot/develop/headers/os/locale", System, false);
286     AddPath("/boot/develop/headers/os/mail", System, false);
287     AddPath("/boot/develop/headers/os/media", System, false);
288     AddPath("/boot/develop/headers/os/midi", System, false);
289     AddPath("/boot/develop/headers/os/midi2", System, false);
290     AddPath("/boot/develop/headers/os/net", System, false);
291     AddPath("/boot/develop/headers/os/storage", System, false);
292     AddPath("/boot/develop/headers/os/support", System, false);
293     AddPath("/boot/develop/headers/os/translation", System, false);
294     AddPath("/boot/develop/headers/os/add-ons/graphics", System, false);
295     AddPath("/boot/develop/headers/os/add-ons/input_server", System, false);
296     AddPath("/boot/develop/headers/os/add-ons/screen_saver", System, false);
297     AddPath("/boot/develop/headers/os/add-ons/tracker", System, false);
298     AddPath("/boot/develop/headers/os/be_apps/Deskbar", System, false);
299     AddPath("/boot/develop/headers/os/be_apps/NetPositive", System, false);
300     AddPath("/boot/develop/headers/os/be_apps/Tracker", System, false);
301     AddPath("/boot/develop/headers/cpp", System, false);
302     AddPath("/boot/develop/headers/cpp/i586-pc-haiku", System, false);
303     AddPath("/boot/develop/headers/3rdparty", System, false);
304     AddPath("/boot/develop/headers/bsd", System, false);
305     AddPath("/boot/develop/headers/glibc", System, false);
306     AddPath("/boot/develop/headers/posix", System, false);
307     AddPath("/boot/develop/headers",  System, false);
308     break;
309   case llvm::Triple::RTEMS:
310     break;
311   case llvm::Triple::Cygwin:
312     AddPath("/usr/include/w32api", System, false);
313     break;
314   case llvm::Triple::MinGW32: {
315       // mingw-w64 crt include paths
316       // <sysroot>/i686-w64-mingw32/include
317       SmallString<128> P = StringRef(HSOpts.ResourceDir);
318       llvm::sys::path::append(P, "../../../i686-w64-mingw32/include");
319       AddPath(P.str(), System, false);
320 
321       // <sysroot>/x86_64-w64-mingw32/include
322       P.resize(HSOpts.ResourceDir.size());
323       llvm::sys::path::append(P, "../../../x86_64-w64-mingw32/include");
324       AddPath(P.str(), System, false);
325 
326       // mingw.org crt include paths
327       // <sysroot>/include
328       P.resize(HSOpts.ResourceDir.size());
329       llvm::sys::path::append(P, "../../../include");
330       AddPath(P.str(), System, false);
331       AddPath("/mingw/include", System, false);
332 #if defined(_WIN32)
333       AddPath("c:/mingw/include", System, false);
334 #endif
335     }
336     break;
337 
338   default:
339     break;
340   }
341 
342   if ( os != llvm::Triple::RTEMS )
343     AddPath("/usr/include", ExternCSystem, false);
344 }
345 
346 void InitHeaderSearch::
347 AddDefaultCPlusPlusIncludePaths(const llvm::Triple &triple, const HeaderSearchOptions &HSOpts) {
348   llvm::Triple::OSType os = triple.getOS();
349   // FIXME: temporary hack: hard-coded paths.
350 
351   if (triple.isOSDarwin()) {
352     switch (triple.getArch()) {
353     default: break;
354 
355     case llvm::Triple::ppc:
356     case llvm::Triple::ppc64:
357       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
358                                   "powerpc-apple-darwin10", "", "ppc64",
359                                   triple);
360       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.0.0",
361                                   "powerpc-apple-darwin10", "", "ppc64",
362                                   triple);
363       break;
364 
365     case llvm::Triple::x86:
366     case llvm::Triple::x86_64:
367       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
368                                   "i686-apple-darwin10", "", "x86_64", triple);
369       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.0.0",
370                                   "i686-apple-darwin8", "", "", triple);
371       break;
372 
373     case llvm::Triple::arm:
374     case llvm::Triple::thumb:
375       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
376                                   "arm-apple-darwin10", "v7", "", triple);
377       AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2.1",
378                                   "arm-apple-darwin10", "v6", "", triple);
379       break;
380     }
381     return;
382   }
383 
384   switch (os) {
385   case llvm::Triple::Linux:
386   case llvm::Triple::Win32:
387     llvm_unreachable("Include management is handled in the driver.");
388 
389   case llvm::Triple::Cygwin:
390     // Cygwin-1.7
391     AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.7.3");
392     AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.5.3");
393     AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.4");
394     // g++-4 / Cygwin-1.5
395     AddMinGWCPlusPlusIncludePaths("/usr/lib/gcc", "i686-pc-cygwin", "4.3.2");
396     break;
397   case llvm::Triple::MinGW32:
398     // mingw-w64 C++ include paths (i686-w64-mingw32 and x86_64-w64-mingw32)
399     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.0");
400     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.1");
401     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.2");
402     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.3");
403     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.5.4");
404     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.0");
405     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.1");
406     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.2");
407     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.6.3");
408     AddMinGW64CXXPaths(HSOpts.ResourceDir, "4.7.0");
409     // mingw.org C++ include paths
410     AddMinGWCPlusPlusIncludePaths("/mingw/lib/gcc", "mingw32", "4.5.2"); //MSYS
411 #if defined(_WIN32)
412     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.8.1");
413     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.6.2");
414     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.6.1");
415     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.5.2");
416     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.5.0");
417     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.4.0");
418     AddMinGWCPlusPlusIncludePaths("c:/MinGW/lib/gcc", "mingw32", "4.3.0");
419 #endif
420     break;
421   case llvm::Triple::DragonFly:
422     if (llvm::sys::fs::exists("/usr/lib/gcc47"))
423       AddPath("/usr/include/c++/4.7", CXXSystem, false);
424     else
425       AddPath("/usr/include/c++/4.4", CXXSystem, false);
426     break;
427   case llvm::Triple::FreeBSD:
428     // FreeBSD 8.0
429     // FreeBSD 7.3
430     AddGnuCPlusPlusIncludePaths("/usr/include/c++/4.2", "", "", "", triple);
431     break;
432   case llvm::Triple::OpenBSD: {
433     std::string t = triple.getTriple();
434     if (t.substr(0, 6) == "x86_64")
435       t.replace(0, 6, "amd64");
436     AddGnuCPlusPlusIncludePaths("/usr/include/g++",
437                                 t, "", "", triple);
438     break;
439   }
440   case llvm::Triple::Solaris:
441     AddGnuCPlusPlusIncludePaths("/usr/gcc/4.5/include/c++/4.5.2/",
442                                 "i386-pc-solaris2.11", "", "", triple);
443     // Solaris - Fall though..
444   case llvm::Triple::AuroraUX:
445     // AuroraUX
446     AddGnuCPlusPlusIncludePaths("/opt/gcc4/include/c++/4.2.4",
447                                 "i386-pc-solaris2.11", "", "", triple);
448     break;
449   default:
450     break;
451   }
452 }
453 
454 void InitHeaderSearch::AddDefaultIncludePaths(const LangOptions &Lang,
455                                               const llvm::Triple &triple,
456                                             const HeaderSearchOptions &HSOpts) {
457   // NB: This code path is going away. All of the logic is moving into the
458   // driver which has the information necessary to do target-specific
459   // selections of default include paths. Each target which moves there will be
460   // exempted from this logic here until we can delete the entire pile of code.
461   switch (triple.getOS()) {
462   default:
463     break; // Everything else continues to use this routine's logic.
464 
465   case llvm::Triple::Linux:
466   case llvm::Triple::Win32:
467     return;
468   }
469 
470   if (Lang.CPlusPlus && HSOpts.UseStandardCXXIncludes &&
471       HSOpts.UseStandardSystemIncludes) {
472     if (HSOpts.UseLibcxx) {
473       if (triple.isOSDarwin()) {
474         // On Darwin, libc++ may be installed alongside the compiler in
475         // include/c++/v1.
476         if (!HSOpts.ResourceDir.empty()) {
477           // Remove version from foo/lib/clang/version
478           StringRef NoVer = llvm::sys::path::parent_path(HSOpts.ResourceDir);
479           // Remove clang from foo/lib/clang
480           StringRef Lib = llvm::sys::path::parent_path(NoVer);
481           // Remove lib from foo/lib
482           SmallString<128> P = llvm::sys::path::parent_path(Lib);
483 
484           // Get foo/include/c++/v1
485           llvm::sys::path::append(P, "include", "c++", "v1");
486           AddUnmappedPath(P.str(), CXXSystem, false);
487         }
488       }
489       // On Solaris, include the support directory for things like xlocale and
490       // fudged system headers.
491       if (triple.getOS() == llvm::Triple::Solaris)
492         AddPath("/usr/include/c++/v1/support/solaris", CXXSystem, false);
493 
494       AddPath("/usr/include/c++/v1", CXXSystem, false);
495     } else {
496       AddDefaultCPlusPlusIncludePaths(triple, HSOpts);
497     }
498   }
499 
500   AddDefaultCIncludePaths(triple, HSOpts);
501 
502   // Add the default framework include paths on Darwin.
503   if (HSOpts.UseStandardSystemIncludes) {
504     if (triple.isOSDarwin()) {
505       AddPath("/System/Library/Frameworks", System, true);
506       AddPath("/Library/Frameworks", System, true);
507     }
508   }
509 }
510 
511 /// RemoveDuplicates - If there are duplicate directory entries in the specified
512 /// search list, remove the later (dead) ones.  Returns the number of non-system
513 /// headers removed, which is used to update NumAngled.
514 static unsigned RemoveDuplicates(std::vector<DirectoryLookup> &SearchList,
515                                  unsigned First, bool Verbose) {
516   llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenDirs;
517   llvm::SmallPtrSet<const DirectoryEntry *, 8> SeenFrameworkDirs;
518   llvm::SmallPtrSet<const HeaderMap *, 8> SeenHeaderMaps;
519   unsigned NonSystemRemoved = 0;
520   for (unsigned i = First; i != SearchList.size(); ++i) {
521     unsigned DirToRemove = i;
522 
523     const DirectoryLookup &CurEntry = SearchList[i];
524 
525     if (CurEntry.isNormalDir()) {
526       // If this isn't the first time we've seen this dir, remove it.
527       if (SeenDirs.insert(CurEntry.getDir()))
528         continue;
529     } else if (CurEntry.isFramework()) {
530       // If this isn't the first time we've seen this framework dir, remove it.
531       if (SeenFrameworkDirs.insert(CurEntry.getFrameworkDir()))
532         continue;
533     } else {
534       assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
535       // If this isn't the first time we've seen this headermap, remove it.
536       if (SeenHeaderMaps.insert(CurEntry.getHeaderMap()))
537         continue;
538     }
539 
540     // If we have a normal #include dir/framework/headermap that is shadowed
541     // later in the chain by a system include location, we actually want to
542     // ignore the user's request and drop the user dir... keeping the system
543     // dir.  This is weird, but required to emulate GCC's search path correctly.
544     //
545     // Since dupes of system dirs are rare, just rescan to find the original
546     // that we're nuking instead of using a DenseMap.
547     if (CurEntry.getDirCharacteristic() != SrcMgr::C_User) {
548       // Find the dir that this is the same of.
549       unsigned FirstDir;
550       for (FirstDir = 0; ; ++FirstDir) {
551         assert(FirstDir != i && "Didn't find dupe?");
552 
553         const DirectoryLookup &SearchEntry = SearchList[FirstDir];
554 
555         // If these are different lookup types, then they can't be the dupe.
556         if (SearchEntry.getLookupType() != CurEntry.getLookupType())
557           continue;
558 
559         bool isSame;
560         if (CurEntry.isNormalDir())
561           isSame = SearchEntry.getDir() == CurEntry.getDir();
562         else if (CurEntry.isFramework())
563           isSame = SearchEntry.getFrameworkDir() == CurEntry.getFrameworkDir();
564         else {
565           assert(CurEntry.isHeaderMap() && "Not a headermap or normal dir?");
566           isSame = SearchEntry.getHeaderMap() == CurEntry.getHeaderMap();
567         }
568 
569         if (isSame)
570           break;
571       }
572 
573       // If the first dir in the search path is a non-system dir, zap it
574       // instead of the system one.
575       if (SearchList[FirstDir].getDirCharacteristic() == SrcMgr::C_User)
576         DirToRemove = FirstDir;
577     }
578 
579     if (Verbose) {
580       llvm::errs() << "ignoring duplicate directory \""
581                    << CurEntry.getName() << "\"\n";
582       if (DirToRemove != i)
583         llvm::errs() << "  as it is a non-system directory that duplicates "
584                      << "a system directory\n";
585     }
586     if (DirToRemove != i)
587       ++NonSystemRemoved;
588 
589     // This is reached if the current entry is a duplicate.  Remove the
590     // DirToRemove (usually the current dir).
591     SearchList.erase(SearchList.begin()+DirToRemove);
592     --i;
593   }
594   return NonSystemRemoved;
595 }
596 
597 
598 void InitHeaderSearch::Realize(const LangOptions &Lang) {
599   // Concatenate ANGLE+SYSTEM+AFTER chains together into SearchList.
600   std::vector<DirectoryLookup> SearchList;
601   SearchList.reserve(IncludePath.size());
602 
603   // Quoted arguments go first.
604   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
605        it != ie; ++it) {
606     if (it->first == Quoted)
607       SearchList.push_back(it->second);
608   }
609   // Deduplicate and remember index.
610   RemoveDuplicates(SearchList, 0, Verbose);
611   unsigned NumQuoted = SearchList.size();
612 
613   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
614        it != ie; ++it) {
615     if (it->first == Angled || it->first == IndexHeaderMap)
616       SearchList.push_back(it->second);
617   }
618 
619   RemoveDuplicates(SearchList, NumQuoted, Verbose);
620   unsigned NumAngled = SearchList.size();
621 
622   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
623        it != ie; ++it) {
624     if (it->first == System || it->first == ExternCSystem ||
625         (!Lang.ObjC1 && !Lang.CPlusPlus && it->first == CSystem)    ||
626         (/*FIXME !Lang.ObjC1 && */Lang.CPlusPlus  && it->first == CXXSystem)  ||
627         (Lang.ObjC1  && !Lang.CPlusPlus && it->first == ObjCSystem) ||
628         (Lang.ObjC1  && Lang.CPlusPlus  && it->first == ObjCXXSystem))
629       SearchList.push_back(it->second);
630   }
631 
632   for (path_iterator it = IncludePath.begin(), ie = IncludePath.end();
633        it != ie; ++it) {
634     if (it->first == After)
635       SearchList.push_back(it->second);
636   }
637 
638   // Remove duplicates across both the Angled and System directories.  GCC does
639   // this and failing to remove duplicates across these two groups breaks
640   // #include_next.
641   unsigned NonSystemRemoved = RemoveDuplicates(SearchList, NumQuoted, Verbose);
642   NumAngled -= NonSystemRemoved;
643 
644   bool DontSearchCurDir = false;  // TODO: set to true if -I- is set?
645   Headers.SetSearchPaths(SearchList, NumQuoted, NumAngled, DontSearchCurDir);
646 
647   Headers.SetSystemHeaderPrefixes(SystemHeaderPrefixes);
648 
649   // If verbose, print the list of directories that will be searched.
650   if (Verbose) {
651     llvm::errs() << "#include \"...\" search starts here:\n";
652     for (unsigned i = 0, e = SearchList.size(); i != e; ++i) {
653       if (i == NumQuoted)
654         llvm::errs() << "#include <...> search starts here:\n";
655       const char *Name = SearchList[i].getName();
656       const char *Suffix;
657       if (SearchList[i].isNormalDir())
658         Suffix = "";
659       else if (SearchList[i].isFramework())
660         Suffix = " (framework directory)";
661       else {
662         assert(SearchList[i].isHeaderMap() && "Unknown DirectoryLookup");
663         Suffix = " (headermap)";
664       }
665       llvm::errs() << " " << Name << Suffix << "\n";
666     }
667     llvm::errs() << "End of search list.\n";
668   }
669 }
670 
671 void clang::ApplyHeaderSearchOptions(HeaderSearch &HS,
672                                      const HeaderSearchOptions &HSOpts,
673                                      const LangOptions &Lang,
674                                      const llvm::Triple &Triple) {
675   InitHeaderSearch Init(HS, HSOpts.Verbose, HSOpts.Sysroot);
676 
677   // Add the user defined entries.
678   for (unsigned i = 0, e = HSOpts.UserEntries.size(); i != e; ++i) {
679     const HeaderSearchOptions::Entry &E = HSOpts.UserEntries[i];
680     if (E.IgnoreSysRoot) {
681       Init.AddUnmappedPath(E.Path, E.Group, E.IsFramework);
682     } else {
683       Init.AddPath(E.Path, E.Group, E.IsFramework);
684     }
685   }
686 
687   Init.AddDefaultIncludePaths(Lang, Triple, HSOpts);
688 
689   for (unsigned i = 0, e = HSOpts.SystemHeaderPrefixes.size(); i != e; ++i)
690     Init.AddSystemHeaderPrefix(HSOpts.SystemHeaderPrefixes[i].Prefix,
691                                HSOpts.SystemHeaderPrefixes[i].IsSystemHeader);
692 
693   if (HSOpts.UseBuiltinIncludes) {
694     // Set up the builtin include directory in the module map.
695     SmallString<128> P = StringRef(HSOpts.ResourceDir);
696     llvm::sys::path::append(P, "include");
697     if (const DirectoryEntry *Dir = HS.getFileMgr().getDirectory(P.str()))
698       HS.getModuleMap().setBuiltinIncludeDir(Dir);
699   }
700 
701   Init.Realize(Lang);
702 }
703