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1 //===--- HeaderSearch.cpp - Resolve Header File Locations ---===//
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 DirectoryLookup and HeaderSearch interfaces.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "clang/Lex/HeaderSearch.h"
15 #include "clang/Basic/FileManager.h"
16 #include "clang/Basic/IdentifierTable.h"
17 #include "clang/Lex/ExternalPreprocessorSource.h"
18 #include "clang/Lex/HeaderMap.h"
19 #include "clang/Lex/HeaderSearchOptions.h"
20 #include "clang/Lex/LexDiagnostic.h"
21 #include "clang/Lex/Lexer.h"
22 #include "clang/Lex/Preprocessor.h"
23 #include "llvm/ADT/APInt.h"
24 #include "llvm/ADT/Hashing.h"
25 #include "llvm/ADT/SmallString.h"
26 #include "llvm/Support/Capacity.h"
27 #include "llvm/Support/FileSystem.h"
28 #include "llvm/Support/Path.h"
29 #include "llvm/Support/raw_ostream.h"
30 #include <cstdio>
31 #include <utility>
32 #if defined(LLVM_ON_UNIX)
33 #include <limits.h>
34 #endif
35 using namespace clang;
36 
37 const IdentifierInfo *
getControllingMacro(ExternalPreprocessorSource * External)38 HeaderFileInfo::getControllingMacro(ExternalPreprocessorSource *External) {
39   if (ControllingMacro) {
40     if (ControllingMacro->isOutOfDate())
41       External->updateOutOfDateIdentifier(
42           *const_cast<IdentifierInfo *>(ControllingMacro));
43     return ControllingMacro;
44   }
45 
46   if (!ControllingMacroID || !External)
47     return nullptr;
48 
49   ControllingMacro = External->GetIdentifier(ControllingMacroID);
50   return ControllingMacro;
51 }
52 
~ExternalHeaderFileInfoSource()53 ExternalHeaderFileInfoSource::~ExternalHeaderFileInfoSource() {}
54 
HeaderSearch(IntrusiveRefCntPtr<HeaderSearchOptions> HSOpts,SourceManager & SourceMgr,DiagnosticsEngine & Diags,const LangOptions & LangOpts,const TargetInfo * Target)55 HeaderSearch::HeaderSearch(IntrusiveRefCntPtr<HeaderSearchOptions> HSOpts,
56                            SourceManager &SourceMgr, DiagnosticsEngine &Diags,
57                            const LangOptions &LangOpts,
58                            const TargetInfo *Target)
59     : HSOpts(std::move(HSOpts)), Diags(Diags),
60       FileMgr(SourceMgr.getFileManager()), FrameworkMap(64),
61       ModMap(SourceMgr, Diags, LangOpts, Target, *this) {
62   AngledDirIdx = 0;
63   SystemDirIdx = 0;
64   NoCurDirSearch = false;
65 
66   ExternalLookup = nullptr;
67   ExternalSource = nullptr;
68   NumIncluded = 0;
69   NumMultiIncludeFileOptzn = 0;
70   NumFrameworkLookups = NumSubFrameworkLookups = 0;
71 }
72 
~HeaderSearch()73 HeaderSearch::~HeaderSearch() {
74   // Delete headermaps.
75   for (unsigned i = 0, e = HeaderMaps.size(); i != e; ++i)
76     delete HeaderMaps[i].second;
77 }
78 
PrintStats()79 void HeaderSearch::PrintStats() {
80   fprintf(stderr, "\n*** HeaderSearch Stats:\n");
81   fprintf(stderr, "%d files tracked.\n", (int)FileInfo.size());
82   unsigned NumOnceOnlyFiles = 0, MaxNumIncludes = 0, NumSingleIncludedFiles = 0;
83   for (unsigned i = 0, e = FileInfo.size(); i != e; ++i) {
84     NumOnceOnlyFiles += FileInfo[i].isImport;
85     if (MaxNumIncludes < FileInfo[i].NumIncludes)
86       MaxNumIncludes = FileInfo[i].NumIncludes;
87     NumSingleIncludedFiles += FileInfo[i].NumIncludes == 1;
88   }
89   fprintf(stderr, "  %d #import/#pragma once files.\n", NumOnceOnlyFiles);
90   fprintf(stderr, "  %d included exactly once.\n", NumSingleIncludedFiles);
91   fprintf(stderr, "  %d max times a file is included.\n", MaxNumIncludes);
92 
93   fprintf(stderr, "  %d #include/#include_next/#import.\n", NumIncluded);
94   fprintf(stderr, "    %d #includes skipped due to"
95           " the multi-include optimization.\n", NumMultiIncludeFileOptzn);
96 
97   fprintf(stderr, "%d framework lookups.\n", NumFrameworkLookups);
98   fprintf(stderr, "%d subframework lookups.\n", NumSubFrameworkLookups);
99 }
100 
101 /// CreateHeaderMap - This method returns a HeaderMap for the specified
102 /// FileEntry, uniquing them through the 'HeaderMaps' datastructure.
CreateHeaderMap(const FileEntry * FE)103 const HeaderMap *HeaderSearch::CreateHeaderMap(const FileEntry *FE) {
104   // We expect the number of headermaps to be small, and almost always empty.
105   // If it ever grows, use of a linear search should be re-evaluated.
106   if (!HeaderMaps.empty()) {
107     for (unsigned i = 0, e = HeaderMaps.size(); i != e; ++i)
108       // Pointer equality comparison of FileEntries works because they are
109       // already uniqued by inode.
110       if (HeaderMaps[i].first == FE)
111         return HeaderMaps[i].second;
112   }
113 
114   if (const HeaderMap *HM = HeaderMap::Create(FE, FileMgr)) {
115     HeaderMaps.push_back(std::make_pair(FE, HM));
116     return HM;
117   }
118 
119   return nullptr;
120 }
121 
getModuleFileName(Module * Module)122 std::string HeaderSearch::getModuleFileName(Module *Module) {
123   const FileEntry *ModuleMap =
124       getModuleMap().getModuleMapFileForUniquing(Module);
125   return getModuleFileName(Module->Name, ModuleMap->getName());
126 }
127 
getModuleFileName(StringRef ModuleName,StringRef ModuleMapPath)128 std::string HeaderSearch::getModuleFileName(StringRef ModuleName,
129                                             StringRef ModuleMapPath) {
130   // If we don't have a module cache path or aren't supposed to use one, we
131   // can't do anything.
132   if (getModuleCachePath().empty())
133     return std::string();
134 
135   SmallString<256> Result(getModuleCachePath());
136   llvm::sys::fs::make_absolute(Result);
137 
138   if (HSOpts->DisableModuleHash) {
139     llvm::sys::path::append(Result, ModuleName + ".pcm");
140   } else {
141     // Construct the name <ModuleName>-<hash of ModuleMapPath>.pcm which should
142     // ideally be globally unique to this particular module. Name collisions
143     // in the hash are safe (because any translation unit can only import one
144     // module with each name), but result in a loss of caching.
145     //
146     // To avoid false-negatives, we form as canonical a path as we can, and map
147     // to lower-case in case we're on a case-insensitive file system.
148    auto *Dir =
149         FileMgr.getDirectory(llvm::sys::path::parent_path(ModuleMapPath));
150     if (!Dir)
151       return std::string();
152     auto DirName = FileMgr.getCanonicalName(Dir);
153     auto FileName = llvm::sys::path::filename(ModuleMapPath);
154 
155     llvm::hash_code Hash =
156       llvm::hash_combine(DirName.lower(), FileName.lower());
157 
158     SmallString<128> HashStr;
159     llvm::APInt(64, size_t(Hash)).toStringUnsigned(HashStr, /*Radix*/36);
160     llvm::sys::path::append(Result, ModuleName + "-" + HashStr + ".pcm");
161   }
162   return Result.str().str();
163 }
164 
lookupModule(StringRef ModuleName,bool AllowSearch)165 Module *HeaderSearch::lookupModule(StringRef ModuleName, bool AllowSearch) {
166   // Look in the module map to determine if there is a module by this name.
167   Module *Module = ModMap.findModule(ModuleName);
168   if (Module || !AllowSearch || !HSOpts->ImplicitModuleMaps)
169     return Module;
170 
171   // Look through the various header search paths to load any available module
172   // maps, searching for a module map that describes this module.
173   for (unsigned Idx = 0, N = SearchDirs.size(); Idx != N; ++Idx) {
174     if (SearchDirs[Idx].isFramework()) {
175       // Search for or infer a module map for a framework.
176       SmallString<128> FrameworkDirName;
177       FrameworkDirName += SearchDirs[Idx].getFrameworkDir()->getName();
178       llvm::sys::path::append(FrameworkDirName, ModuleName + ".framework");
179       if (const DirectoryEntry *FrameworkDir
180             = FileMgr.getDirectory(FrameworkDirName)) {
181         bool IsSystem
182           = SearchDirs[Idx].getDirCharacteristic() != SrcMgr::C_User;
183         Module = loadFrameworkModule(ModuleName, FrameworkDir, IsSystem);
184         if (Module)
185           break;
186       }
187     }
188 
189     // FIXME: Figure out how header maps and module maps will work together.
190 
191     // Only deal with normal search directories.
192     if (!SearchDirs[Idx].isNormalDir())
193       continue;
194 
195     bool IsSystem = SearchDirs[Idx].isSystemHeaderDirectory();
196     // Search for a module map file in this directory.
197     if (loadModuleMapFile(SearchDirs[Idx].getDir(), IsSystem,
198                           /*IsFramework*/false) == LMM_NewlyLoaded) {
199       // We just loaded a module map file; check whether the module is
200       // available now.
201       Module = ModMap.findModule(ModuleName);
202       if (Module)
203         break;
204     }
205 
206     // Search for a module map in a subdirectory with the same name as the
207     // module.
208     SmallString<128> NestedModuleMapDirName;
209     NestedModuleMapDirName = SearchDirs[Idx].getDir()->getName();
210     llvm::sys::path::append(NestedModuleMapDirName, ModuleName);
211     if (loadModuleMapFile(NestedModuleMapDirName, IsSystem,
212                           /*IsFramework*/false) == LMM_NewlyLoaded){
213       // If we just loaded a module map file, look for the module again.
214       Module = ModMap.findModule(ModuleName);
215       if (Module)
216         break;
217     }
218 
219     // If we've already performed the exhaustive search for module maps in this
220     // search directory, don't do it again.
221     if (SearchDirs[Idx].haveSearchedAllModuleMaps())
222       continue;
223 
224     // Load all module maps in the immediate subdirectories of this search
225     // directory.
226     loadSubdirectoryModuleMaps(SearchDirs[Idx]);
227 
228     // Look again for the module.
229     Module = ModMap.findModule(ModuleName);
230     if (Module)
231       break;
232   }
233 
234   return Module;
235 }
236 
237 //===----------------------------------------------------------------------===//
238 // File lookup within a DirectoryLookup scope
239 //===----------------------------------------------------------------------===//
240 
241 /// getName - Return the directory or filename corresponding to this lookup
242 /// object.
getName() const243 const char *DirectoryLookup::getName() const {
244   if (isNormalDir())
245     return getDir()->getName();
246   if (isFramework())
247     return getFrameworkDir()->getName();
248   assert(isHeaderMap() && "Unknown DirectoryLookup");
249   return getHeaderMap()->getFileName();
250 }
251 
getFileAndSuggestModule(StringRef FileName,SourceLocation IncludeLoc,const DirectoryEntry * Dir,bool IsSystemHeaderDir,Module * RequestingModule,ModuleMap::KnownHeader * SuggestedModule)252 const FileEntry *HeaderSearch::getFileAndSuggestModule(
253     StringRef FileName, SourceLocation IncludeLoc, const DirectoryEntry *Dir,
254     bool IsSystemHeaderDir, Module *RequestingModule,
255     ModuleMap::KnownHeader *SuggestedModule) {
256   // If we have a module map that might map this header, load it and
257   // check whether we'll have a suggestion for a module.
258   const FileEntry *File = getFileMgr().getFile(FileName, /*OpenFile=*/true);
259   if (!File)
260     return nullptr;
261 
262   // If there is a module that corresponds to this header, suggest it.
263   if (!findUsableModuleForHeader(File, Dir ? Dir : File->getDir(),
264                                  RequestingModule, SuggestedModule,
265                                  IsSystemHeaderDir))
266     return nullptr;
267 
268   return File;
269 }
270 
271 /// LookupFile - Lookup the specified file in this search path, returning it
272 /// if it exists or returning null if not.
LookupFile(StringRef & Filename,HeaderSearch & HS,SourceLocation IncludeLoc,SmallVectorImpl<char> * SearchPath,SmallVectorImpl<char> * RelativePath,Module * RequestingModule,ModuleMap::KnownHeader * SuggestedModule,bool & InUserSpecifiedSystemFramework,bool & HasBeenMapped,SmallVectorImpl<char> & MappedName) const273 const FileEntry *DirectoryLookup::LookupFile(
274     StringRef &Filename,
275     HeaderSearch &HS,
276     SourceLocation IncludeLoc,
277     SmallVectorImpl<char> *SearchPath,
278     SmallVectorImpl<char> *RelativePath,
279     Module *RequestingModule,
280     ModuleMap::KnownHeader *SuggestedModule,
281     bool &InUserSpecifiedSystemFramework,
282     bool &HasBeenMapped,
283     SmallVectorImpl<char> &MappedName) const {
284   InUserSpecifiedSystemFramework = false;
285   HasBeenMapped = false;
286 
287   SmallString<1024> TmpDir;
288   if (isNormalDir()) {
289     // Concatenate the requested file onto the directory.
290     TmpDir = getDir()->getName();
291     llvm::sys::path::append(TmpDir, Filename);
292     if (SearchPath) {
293       StringRef SearchPathRef(getDir()->getName());
294       SearchPath->clear();
295       SearchPath->append(SearchPathRef.begin(), SearchPathRef.end());
296     }
297     if (RelativePath) {
298       RelativePath->clear();
299       RelativePath->append(Filename.begin(), Filename.end());
300     }
301 
302     return HS.getFileAndSuggestModule(TmpDir, IncludeLoc, getDir(),
303                                       isSystemHeaderDirectory(),
304                                       RequestingModule, SuggestedModule);
305   }
306 
307   if (isFramework())
308     return DoFrameworkLookup(Filename, HS, SearchPath, RelativePath,
309                              RequestingModule, SuggestedModule,
310                              InUserSpecifiedSystemFramework);
311 
312   assert(isHeaderMap() && "Unknown directory lookup");
313   const HeaderMap *HM = getHeaderMap();
314   SmallString<1024> Path;
315   StringRef Dest = HM->lookupFilename(Filename, Path);
316   if (Dest.empty())
317     return nullptr;
318 
319   const FileEntry *Result;
320 
321   // Check if the headermap maps the filename to a framework include
322   // ("Foo.h" -> "Foo/Foo.h"), in which case continue header lookup using the
323   // framework include.
324   if (llvm::sys::path::is_relative(Dest)) {
325     MappedName.clear();
326     MappedName.append(Dest.begin(), Dest.end());
327     Filename = StringRef(MappedName.begin(), MappedName.size());
328     HasBeenMapped = true;
329     Result = HM->LookupFile(Filename, HS.getFileMgr());
330 
331   } else {
332     Result = HS.getFileMgr().getFile(Dest);
333   }
334 
335   if (Result) {
336     if (SearchPath) {
337       StringRef SearchPathRef(getName());
338       SearchPath->clear();
339       SearchPath->append(SearchPathRef.begin(), SearchPathRef.end());
340     }
341     if (RelativePath) {
342       RelativePath->clear();
343       RelativePath->append(Filename.begin(), Filename.end());
344     }
345   }
346   return Result;
347 }
348 
349 /// \brief Given a framework directory, find the top-most framework directory.
350 ///
351 /// \param FileMgr The file manager to use for directory lookups.
352 /// \param DirName The name of the framework directory.
353 /// \param SubmodulePath Will be populated with the submodule path from the
354 /// returned top-level module to the originally named framework.
355 static const DirectoryEntry *
getTopFrameworkDir(FileManager & FileMgr,StringRef DirName,SmallVectorImpl<std::string> & SubmodulePath)356 getTopFrameworkDir(FileManager &FileMgr, StringRef DirName,
357                    SmallVectorImpl<std::string> &SubmodulePath) {
358   assert(llvm::sys::path::extension(DirName) == ".framework" &&
359          "Not a framework directory");
360 
361   // Note: as an egregious but useful hack we use the real path here, because
362   // frameworks moving between top-level frameworks to embedded frameworks tend
363   // to be symlinked, and we base the logical structure of modules on the
364   // physical layout. In particular, we need to deal with crazy includes like
365   //
366   //   #include <Foo/Frameworks/Bar.framework/Headers/Wibble.h>
367   //
368   // where 'Bar' used to be embedded in 'Foo', is now a top-level framework
369   // which one should access with, e.g.,
370   //
371   //   #include <Bar/Wibble.h>
372   //
373   // Similar issues occur when a top-level framework has moved into an
374   // embedded framework.
375   const DirectoryEntry *TopFrameworkDir = FileMgr.getDirectory(DirName);
376   DirName = FileMgr.getCanonicalName(TopFrameworkDir);
377   do {
378     // Get the parent directory name.
379     DirName = llvm::sys::path::parent_path(DirName);
380     if (DirName.empty())
381       break;
382 
383     // Determine whether this directory exists.
384     const DirectoryEntry *Dir = FileMgr.getDirectory(DirName);
385     if (!Dir)
386       break;
387 
388     // If this is a framework directory, then we're a subframework of this
389     // framework.
390     if (llvm::sys::path::extension(DirName) == ".framework") {
391       SubmodulePath.push_back(llvm::sys::path::stem(DirName));
392       TopFrameworkDir = Dir;
393     }
394   } while (true);
395 
396   return TopFrameworkDir;
397 }
398 
399 /// DoFrameworkLookup - Do a lookup of the specified file in the current
400 /// DirectoryLookup, which is a framework directory.
DoFrameworkLookup(StringRef Filename,HeaderSearch & HS,SmallVectorImpl<char> * SearchPath,SmallVectorImpl<char> * RelativePath,Module * RequestingModule,ModuleMap::KnownHeader * SuggestedModule,bool & InUserSpecifiedSystemFramework) const401 const FileEntry *DirectoryLookup::DoFrameworkLookup(
402     StringRef Filename, HeaderSearch &HS, SmallVectorImpl<char> *SearchPath,
403     SmallVectorImpl<char> *RelativePath, Module *RequestingModule,
404     ModuleMap::KnownHeader *SuggestedModule,
405     bool &InUserSpecifiedSystemFramework) const {
406   FileManager &FileMgr = HS.getFileMgr();
407 
408   // Framework names must have a '/' in the filename.
409   size_t SlashPos = Filename.find('/');
410   if (SlashPos == StringRef::npos) return nullptr;
411 
412   // Find out if this is the home for the specified framework, by checking
413   // HeaderSearch.  Possible answers are yes/no and unknown.
414   HeaderSearch::FrameworkCacheEntry &CacheEntry =
415     HS.LookupFrameworkCache(Filename.substr(0, SlashPos));
416 
417   // If it is known and in some other directory, fail.
418   if (CacheEntry.Directory && CacheEntry.Directory != getFrameworkDir())
419     return nullptr;
420 
421   // Otherwise, construct the path to this framework dir.
422 
423   // FrameworkName = "/System/Library/Frameworks/"
424   SmallString<1024> FrameworkName;
425   FrameworkName += getFrameworkDir()->getName();
426   if (FrameworkName.empty() || FrameworkName.back() != '/')
427     FrameworkName.push_back('/');
428 
429   // FrameworkName = "/System/Library/Frameworks/Cocoa"
430   StringRef ModuleName(Filename.begin(), SlashPos);
431   FrameworkName += ModuleName;
432 
433   // FrameworkName = "/System/Library/Frameworks/Cocoa.framework/"
434   FrameworkName += ".framework/";
435 
436   // If the cache entry was unresolved, populate it now.
437   if (!CacheEntry.Directory) {
438     HS.IncrementFrameworkLookupCount();
439 
440     // If the framework dir doesn't exist, we fail.
441     const DirectoryEntry *Dir = FileMgr.getDirectory(FrameworkName);
442     if (!Dir) return nullptr;
443 
444     // Otherwise, if it does, remember that this is the right direntry for this
445     // framework.
446     CacheEntry.Directory = getFrameworkDir();
447 
448     // If this is a user search directory, check if the framework has been
449     // user-specified as a system framework.
450     if (getDirCharacteristic() == SrcMgr::C_User) {
451       SmallString<1024> SystemFrameworkMarker(FrameworkName);
452       SystemFrameworkMarker += ".system_framework";
453       if (llvm::sys::fs::exists(SystemFrameworkMarker)) {
454         CacheEntry.IsUserSpecifiedSystemFramework = true;
455       }
456     }
457   }
458 
459   // Set the 'user-specified system framework' flag.
460   InUserSpecifiedSystemFramework = CacheEntry.IsUserSpecifiedSystemFramework;
461 
462   if (RelativePath) {
463     RelativePath->clear();
464     RelativePath->append(Filename.begin()+SlashPos+1, Filename.end());
465   }
466 
467   // Check "/System/Library/Frameworks/Cocoa.framework/Headers/file.h"
468   unsigned OrigSize = FrameworkName.size();
469 
470   FrameworkName += "Headers/";
471 
472   if (SearchPath) {
473     SearchPath->clear();
474     // Without trailing '/'.
475     SearchPath->append(FrameworkName.begin(), FrameworkName.end()-1);
476   }
477 
478   FrameworkName.append(Filename.begin()+SlashPos+1, Filename.end());
479   const FileEntry *FE = FileMgr.getFile(FrameworkName,
480                                         /*openFile=*/!SuggestedModule);
481   if (!FE) {
482     // Check "/System/Library/Frameworks/Cocoa.framework/PrivateHeaders/file.h"
483     const char *Private = "Private";
484     FrameworkName.insert(FrameworkName.begin()+OrigSize, Private,
485                          Private+strlen(Private));
486     if (SearchPath)
487       SearchPath->insert(SearchPath->begin()+OrigSize, Private,
488                          Private+strlen(Private));
489 
490     FE = FileMgr.getFile(FrameworkName, /*openFile=*/!SuggestedModule);
491   }
492 
493   // If we found the header and are allowed to suggest a module, do so now.
494   if (FE && SuggestedModule) {
495     // Find the framework in which this header occurs.
496     StringRef FrameworkPath = FE->getDir()->getName();
497     bool FoundFramework = false;
498     do {
499       // Determine whether this directory exists.
500       const DirectoryEntry *Dir = FileMgr.getDirectory(FrameworkPath);
501       if (!Dir)
502         break;
503 
504       // If this is a framework directory, then we're a subframework of this
505       // framework.
506       if (llvm::sys::path::extension(FrameworkPath) == ".framework") {
507         FoundFramework = true;
508         break;
509       }
510 
511       // Get the parent directory name.
512       FrameworkPath = llvm::sys::path::parent_path(FrameworkPath);
513       if (FrameworkPath.empty())
514         break;
515     } while (true);
516 
517     bool IsSystem = getDirCharacteristic() != SrcMgr::C_User;
518     if (FoundFramework) {
519       if (!HS.findUsableModuleForFrameworkHeader(
520               FE, FrameworkPath, RequestingModule, SuggestedModule, IsSystem))
521         return nullptr;
522     } else {
523       if (!HS.findUsableModuleForHeader(FE, getDir(), RequestingModule,
524                                         SuggestedModule, IsSystem))
525         return nullptr;
526     }
527   }
528   return FE;
529 }
530 
setTarget(const TargetInfo & Target)531 void HeaderSearch::setTarget(const TargetInfo &Target) {
532   ModMap.setTarget(Target);
533 }
534 
535 
536 //===----------------------------------------------------------------------===//
537 // Header File Location.
538 //===----------------------------------------------------------------------===//
539 
540 /// \brief Return true with a diagnostic if the file that MSVC would have found
541 /// fails to match the one that Clang would have found with MSVC header search
542 /// disabled.
checkMSVCHeaderSearch(DiagnosticsEngine & Diags,const FileEntry * MSFE,const FileEntry * FE,SourceLocation IncludeLoc)543 static bool checkMSVCHeaderSearch(DiagnosticsEngine &Diags,
544                                   const FileEntry *MSFE, const FileEntry *FE,
545                                   SourceLocation IncludeLoc) {
546   if (MSFE && FE != MSFE) {
547     Diags.Report(IncludeLoc, diag::ext_pp_include_search_ms) << MSFE->getName();
548     return true;
549   }
550   return false;
551 }
552 
copyString(StringRef Str,llvm::BumpPtrAllocator & Alloc)553 static const char *copyString(StringRef Str, llvm::BumpPtrAllocator &Alloc) {
554   assert(!Str.empty());
555   char *CopyStr = Alloc.Allocate<char>(Str.size()+1);
556   std::copy(Str.begin(), Str.end(), CopyStr);
557   CopyStr[Str.size()] = '\0';
558   return CopyStr;
559 }
560 
561 /// LookupFile - Given a "foo" or \<foo> reference, look up the indicated file,
562 /// return null on failure.  isAngled indicates whether the file reference is
563 /// for system \#include's or not (i.e. using <> instead of ""). Includers, if
564 /// non-empty, indicates where the \#including file(s) are, in case a relative
565 /// search is needed. Microsoft mode will pass all \#including files.
LookupFile(StringRef Filename,SourceLocation IncludeLoc,bool isAngled,const DirectoryLookup * FromDir,const DirectoryLookup * & CurDir,ArrayRef<std::pair<const FileEntry *,const DirectoryEntry * >> Includers,SmallVectorImpl<char> * SearchPath,SmallVectorImpl<char> * RelativePath,Module * RequestingModule,ModuleMap::KnownHeader * SuggestedModule,bool SkipCache,bool BuildSystemModule)566 const FileEntry *HeaderSearch::LookupFile(
567     StringRef Filename, SourceLocation IncludeLoc, bool isAngled,
568     const DirectoryLookup *FromDir, const DirectoryLookup *&CurDir,
569     ArrayRef<std::pair<const FileEntry *, const DirectoryEntry *>> Includers,
570     SmallVectorImpl<char> *SearchPath, SmallVectorImpl<char> *RelativePath,
571     Module *RequestingModule, ModuleMap::KnownHeader *SuggestedModule,
572     bool SkipCache, bool BuildSystemModule) {
573   if (SuggestedModule)
574     *SuggestedModule = ModuleMap::KnownHeader();
575 
576   // If 'Filename' is absolute, check to see if it exists and no searching.
577   if (llvm::sys::path::is_absolute(Filename)) {
578     CurDir = nullptr;
579 
580     // If this was an #include_next "/absolute/file", fail.
581     if (FromDir) return nullptr;
582 
583     if (SearchPath)
584       SearchPath->clear();
585     if (RelativePath) {
586       RelativePath->clear();
587       RelativePath->append(Filename.begin(), Filename.end());
588     }
589     // Otherwise, just return the file.
590     return getFileAndSuggestModule(Filename, IncludeLoc, nullptr,
591                                    /*IsSystemHeaderDir*/false,
592                                    RequestingModule, SuggestedModule);
593   }
594 
595   // This is the header that MSVC's header search would have found.
596   const FileEntry *MSFE = nullptr;
597   ModuleMap::KnownHeader MSSuggestedModule;
598 
599   // Unless disabled, check to see if the file is in the #includer's
600   // directory.  This cannot be based on CurDir, because each includer could be
601   // a #include of a subdirectory (#include "foo/bar.h") and a subsequent
602   // include of "baz.h" should resolve to "whatever/foo/baz.h".
603   // This search is not done for <> headers.
604   if (!Includers.empty() && !isAngled && !NoCurDirSearch) {
605     SmallString<1024> TmpDir;
606     bool First = true;
607     for (const auto &IncluderAndDir : Includers) {
608       const FileEntry *Includer = IncluderAndDir.first;
609 
610       // Concatenate the requested file onto the directory.
611       // FIXME: Portability.  Filename concatenation should be in sys::Path.
612       TmpDir = IncluderAndDir.second->getName();
613       TmpDir.push_back('/');
614       TmpDir.append(Filename.begin(), Filename.end());
615 
616       // FIXME: We don't cache the result of getFileInfo across the call to
617       // getFileAndSuggestModule, because it's a reference to an element of
618       // a container that could be reallocated across this call.
619       //
620       // If we have no includer, that means we're processing a #include
621       // from a module build. We should treat this as a system header if we're
622       // building a [system] module.
623       bool IncluderIsSystemHeader =
624           Includer ? getFileInfo(Includer).DirInfo != SrcMgr::C_User :
625           BuildSystemModule;
626       if (const FileEntry *FE = getFileAndSuggestModule(
627               TmpDir, IncludeLoc, IncluderAndDir.second, IncluderIsSystemHeader,
628               RequestingModule, SuggestedModule)) {
629         if (!Includer) {
630           assert(First && "only first includer can have no file");
631           return FE;
632         }
633 
634         // Leave CurDir unset.
635         // This file is a system header or C++ unfriendly if the old file is.
636         //
637         // Note that we only use one of FromHFI/ToHFI at once, due to potential
638         // reallocation of the underlying vector potentially making the first
639         // reference binding dangling.
640         HeaderFileInfo &FromHFI = getFileInfo(Includer);
641         unsigned DirInfo = FromHFI.DirInfo;
642         bool IndexHeaderMapHeader = FromHFI.IndexHeaderMapHeader;
643         StringRef Framework = FromHFI.Framework;
644 
645         HeaderFileInfo &ToHFI = getFileInfo(FE);
646         ToHFI.DirInfo = DirInfo;
647         ToHFI.IndexHeaderMapHeader = IndexHeaderMapHeader;
648         ToHFI.Framework = Framework;
649 
650         if (SearchPath) {
651           StringRef SearchPathRef(IncluderAndDir.second->getName());
652           SearchPath->clear();
653           SearchPath->append(SearchPathRef.begin(), SearchPathRef.end());
654         }
655         if (RelativePath) {
656           RelativePath->clear();
657           RelativePath->append(Filename.begin(), Filename.end());
658         }
659         if (First)
660           return FE;
661 
662         // Otherwise, we found the path via MSVC header search rules.  If
663         // -Wmsvc-include is enabled, we have to keep searching to see if we
664         // would've found this header in -I or -isystem directories.
665         if (Diags.isIgnored(diag::ext_pp_include_search_ms, IncludeLoc)) {
666           return FE;
667         } else {
668           MSFE = FE;
669           if (SuggestedModule) {
670             MSSuggestedModule = *SuggestedModule;
671             *SuggestedModule = ModuleMap::KnownHeader();
672           }
673           break;
674         }
675       }
676       First = false;
677     }
678   }
679 
680   CurDir = nullptr;
681 
682   // If this is a system #include, ignore the user #include locs.
683   unsigned i = isAngled ? AngledDirIdx : 0;
684 
685   // If this is a #include_next request, start searching after the directory the
686   // file was found in.
687   if (FromDir)
688     i = FromDir-&SearchDirs[0];
689 
690   // Cache all of the lookups performed by this method.  Many headers are
691   // multiply included, and the "pragma once" optimization prevents them from
692   // being relex/pp'd, but they would still have to search through a
693   // (potentially huge) series of SearchDirs to find it.
694   LookupFileCacheInfo &CacheLookup = LookupFileCache[Filename];
695 
696   // If the entry has been previously looked up, the first value will be
697   // non-zero.  If the value is equal to i (the start point of our search), then
698   // this is a matching hit.
699   if (!SkipCache && CacheLookup.StartIdx == i+1) {
700     // Skip querying potentially lots of directories for this lookup.
701     i = CacheLookup.HitIdx;
702     if (CacheLookup.MappedName)
703       Filename = CacheLookup.MappedName;
704   } else {
705     // Otherwise, this is the first query, or the previous query didn't match
706     // our search start.  We will fill in our found location below, so prime the
707     // start point value.
708     CacheLookup.reset(/*StartIdx=*/i+1);
709   }
710 
711   SmallString<64> MappedName;
712 
713   // Check each directory in sequence to see if it contains this file.
714   for (; i != SearchDirs.size(); ++i) {
715     bool InUserSpecifiedSystemFramework = false;
716     bool HasBeenMapped = false;
717     const FileEntry *FE = SearchDirs[i].LookupFile(
718         Filename, *this, IncludeLoc, SearchPath, RelativePath, RequestingModule,
719         SuggestedModule, InUserSpecifiedSystemFramework, HasBeenMapped,
720         MappedName);
721     if (HasBeenMapped) {
722       CacheLookup.MappedName =
723           copyString(Filename, LookupFileCache.getAllocator());
724     }
725     if (!FE) continue;
726 
727     CurDir = &SearchDirs[i];
728 
729     // This file is a system header or C++ unfriendly if the dir is.
730     HeaderFileInfo &HFI = getFileInfo(FE);
731     HFI.DirInfo = CurDir->getDirCharacteristic();
732 
733     // If the directory characteristic is User but this framework was
734     // user-specified to be treated as a system framework, promote the
735     // characteristic.
736     if (HFI.DirInfo == SrcMgr::C_User && InUserSpecifiedSystemFramework)
737       HFI.DirInfo = SrcMgr::C_System;
738 
739     // If the filename matches a known system header prefix, override
740     // whether the file is a system header.
741     for (unsigned j = SystemHeaderPrefixes.size(); j; --j) {
742       if (Filename.startswith(SystemHeaderPrefixes[j-1].first)) {
743         HFI.DirInfo = SystemHeaderPrefixes[j-1].second ? SrcMgr::C_System
744                                                        : SrcMgr::C_User;
745         break;
746       }
747     }
748 
749     // If this file is found in a header map and uses the framework style of
750     // includes, then this header is part of a framework we're building.
751     if (CurDir->isIndexHeaderMap()) {
752       size_t SlashPos = Filename.find('/');
753       if (SlashPos != StringRef::npos) {
754         HFI.IndexHeaderMapHeader = 1;
755         HFI.Framework = getUniqueFrameworkName(StringRef(Filename.begin(),
756                                                          SlashPos));
757       }
758     }
759 
760     if (checkMSVCHeaderSearch(Diags, MSFE, FE, IncludeLoc)) {
761       if (SuggestedModule)
762         *SuggestedModule = MSSuggestedModule;
763       return MSFE;
764     }
765 
766     // Remember this location for the next lookup we do.
767     CacheLookup.HitIdx = i;
768     return FE;
769   }
770 
771   // If we are including a file with a quoted include "foo.h" from inside
772   // a header in a framework that is currently being built, and we couldn't
773   // resolve "foo.h" any other way, change the include to <Foo/foo.h>, where
774   // "Foo" is the name of the framework in which the including header was found.
775   if (!Includers.empty() && Includers.front().first && !isAngled &&
776       Filename.find('/') == StringRef::npos) {
777     HeaderFileInfo &IncludingHFI = getFileInfo(Includers.front().first);
778     if (IncludingHFI.IndexHeaderMapHeader) {
779       SmallString<128> ScratchFilename;
780       ScratchFilename += IncludingHFI.Framework;
781       ScratchFilename += '/';
782       ScratchFilename += Filename;
783 
784       const FileEntry *FE =
785           LookupFile(ScratchFilename, IncludeLoc, /*isAngled=*/true, FromDir,
786                      CurDir, Includers.front(), SearchPath, RelativePath,
787                      RequestingModule, SuggestedModule);
788 
789       if (checkMSVCHeaderSearch(Diags, MSFE, FE, IncludeLoc)) {
790         if (SuggestedModule)
791           *SuggestedModule = MSSuggestedModule;
792         return MSFE;
793       }
794 
795       LookupFileCacheInfo &CacheLookup = LookupFileCache[Filename];
796       CacheLookup.HitIdx = LookupFileCache[ScratchFilename].HitIdx;
797       // FIXME: SuggestedModule.
798       return FE;
799     }
800   }
801 
802   if (checkMSVCHeaderSearch(Diags, MSFE, nullptr, IncludeLoc)) {
803     if (SuggestedModule)
804       *SuggestedModule = MSSuggestedModule;
805     return MSFE;
806   }
807 
808   // Otherwise, didn't find it. Remember we didn't find this.
809   CacheLookup.HitIdx = SearchDirs.size();
810   return nullptr;
811 }
812 
813 /// LookupSubframeworkHeader - Look up a subframework for the specified
814 /// \#include file.  For example, if \#include'ing <HIToolbox/HIToolbox.h> from
815 /// within ".../Carbon.framework/Headers/Carbon.h", check to see if HIToolbox
816 /// is a subframework within Carbon.framework.  If so, return the FileEntry
817 /// for the designated file, otherwise return null.
818 const FileEntry *HeaderSearch::
LookupSubframeworkHeader(StringRef Filename,const FileEntry * ContextFileEnt,SmallVectorImpl<char> * SearchPath,SmallVectorImpl<char> * RelativePath,Module * RequestingModule,ModuleMap::KnownHeader * SuggestedModule)819 LookupSubframeworkHeader(StringRef Filename,
820                          const FileEntry *ContextFileEnt,
821                          SmallVectorImpl<char> *SearchPath,
822                          SmallVectorImpl<char> *RelativePath,
823                          Module *RequestingModule,
824                          ModuleMap::KnownHeader *SuggestedModule) {
825   assert(ContextFileEnt && "No context file?");
826 
827   // Framework names must have a '/' in the filename.  Find it.
828   // FIXME: Should we permit '\' on Windows?
829   size_t SlashPos = Filename.find('/');
830   if (SlashPos == StringRef::npos) return nullptr;
831 
832   // Look up the base framework name of the ContextFileEnt.
833   const char *ContextName = ContextFileEnt->getName();
834 
835   // If the context info wasn't a framework, couldn't be a subframework.
836   const unsigned DotFrameworkLen = 10;
837   const char *FrameworkPos = strstr(ContextName, ".framework");
838   if (FrameworkPos == nullptr ||
839       (FrameworkPos[DotFrameworkLen] != '/' &&
840        FrameworkPos[DotFrameworkLen] != '\\'))
841     return nullptr;
842 
843   SmallString<1024> FrameworkName(ContextName, FrameworkPos+DotFrameworkLen+1);
844 
845   // Append Frameworks/HIToolbox.framework/
846   FrameworkName += "Frameworks/";
847   FrameworkName.append(Filename.begin(), Filename.begin()+SlashPos);
848   FrameworkName += ".framework/";
849 
850   auto &CacheLookup =
851       *FrameworkMap.insert(std::make_pair(Filename.substr(0, SlashPos),
852                                           FrameworkCacheEntry())).first;
853 
854   // Some other location?
855   if (CacheLookup.second.Directory &&
856       CacheLookup.first().size() == FrameworkName.size() &&
857       memcmp(CacheLookup.first().data(), &FrameworkName[0],
858              CacheLookup.first().size()) != 0)
859     return nullptr;
860 
861   // Cache subframework.
862   if (!CacheLookup.second.Directory) {
863     ++NumSubFrameworkLookups;
864 
865     // If the framework dir doesn't exist, we fail.
866     const DirectoryEntry *Dir = FileMgr.getDirectory(FrameworkName);
867     if (!Dir) return nullptr;
868 
869     // Otherwise, if it does, remember that this is the right direntry for this
870     // framework.
871     CacheLookup.second.Directory = Dir;
872   }
873 
874   const FileEntry *FE = nullptr;
875 
876   if (RelativePath) {
877     RelativePath->clear();
878     RelativePath->append(Filename.begin()+SlashPos+1, Filename.end());
879   }
880 
881   // Check ".../Frameworks/HIToolbox.framework/Headers/HIToolbox.h"
882   SmallString<1024> HeadersFilename(FrameworkName);
883   HeadersFilename += "Headers/";
884   if (SearchPath) {
885     SearchPath->clear();
886     // Without trailing '/'.
887     SearchPath->append(HeadersFilename.begin(), HeadersFilename.end()-1);
888   }
889 
890   HeadersFilename.append(Filename.begin()+SlashPos+1, Filename.end());
891   if (!(FE = FileMgr.getFile(HeadersFilename, /*openFile=*/true))) {
892 
893     // Check ".../Frameworks/HIToolbox.framework/PrivateHeaders/HIToolbox.h"
894     HeadersFilename = FrameworkName;
895     HeadersFilename += "PrivateHeaders/";
896     if (SearchPath) {
897       SearchPath->clear();
898       // Without trailing '/'.
899       SearchPath->append(HeadersFilename.begin(), HeadersFilename.end()-1);
900     }
901 
902     HeadersFilename.append(Filename.begin()+SlashPos+1, Filename.end());
903     if (!(FE = FileMgr.getFile(HeadersFilename, /*openFile=*/true)))
904       return nullptr;
905   }
906 
907   // This file is a system header or C++ unfriendly if the old file is.
908   //
909   // Note that the temporary 'DirInfo' is required here, as either call to
910   // getFileInfo could resize the vector and we don't want to rely on order
911   // of evaluation.
912   unsigned DirInfo = getFileInfo(ContextFileEnt).DirInfo;
913   getFileInfo(FE).DirInfo = DirInfo;
914 
915   FrameworkName.pop_back(); // remove the trailing '/'
916   if (!findUsableModuleForFrameworkHeader(FE, FrameworkName, RequestingModule,
917                                           SuggestedModule, /*IsSystem*/ false))
918     return nullptr;
919 
920   return FE;
921 }
922 
923 //===----------------------------------------------------------------------===//
924 // File Info Management.
925 //===----------------------------------------------------------------------===//
926 
927 /// \brief Merge the header file info provided by \p OtherHFI into the current
928 /// header file info (\p HFI)
mergeHeaderFileInfo(HeaderFileInfo & HFI,const HeaderFileInfo & OtherHFI)929 static void mergeHeaderFileInfo(HeaderFileInfo &HFI,
930                                 const HeaderFileInfo &OtherHFI) {
931   assert(OtherHFI.External && "expected to merge external HFI");
932 
933   HFI.isImport |= OtherHFI.isImport;
934   HFI.isPragmaOnce |= OtherHFI.isPragmaOnce;
935   HFI.isModuleHeader |= OtherHFI.isModuleHeader;
936   HFI.NumIncludes += OtherHFI.NumIncludes;
937 
938   if (!HFI.ControllingMacro && !HFI.ControllingMacroID) {
939     HFI.ControllingMacro = OtherHFI.ControllingMacro;
940     HFI.ControllingMacroID = OtherHFI.ControllingMacroID;
941   }
942 
943   HFI.DirInfo = OtherHFI.DirInfo;
944   HFI.External = (!HFI.IsValid || HFI.External);
945   HFI.IsValid = true;
946   HFI.IndexHeaderMapHeader = OtherHFI.IndexHeaderMapHeader;
947 
948   if (HFI.Framework.empty())
949     HFI.Framework = OtherHFI.Framework;
950 }
951 
952 /// getFileInfo - Return the HeaderFileInfo structure for the specified
953 /// FileEntry.
getFileInfo(const FileEntry * FE)954 HeaderFileInfo &HeaderSearch::getFileInfo(const FileEntry *FE) {
955   if (FE->getUID() >= FileInfo.size())
956     FileInfo.resize(FE->getUID() + 1);
957 
958   HeaderFileInfo *HFI = &FileInfo[FE->getUID()];
959   // FIXME: Use a generation count to check whether this is really up to date.
960   if (ExternalSource && !HFI->Resolved) {
961     HFI->Resolved = true;
962     auto ExternalHFI = ExternalSource->GetHeaderFileInfo(FE);
963 
964     HFI = &FileInfo[FE->getUID()];
965     if (ExternalHFI.External)
966       mergeHeaderFileInfo(*HFI, ExternalHFI);
967   }
968 
969   HFI->IsValid = true;
970   // We have local information about this header file, so it's no longer
971   // strictly external.
972   HFI->External = false;
973   return *HFI;
974 }
975 
976 const HeaderFileInfo *
getExistingFileInfo(const FileEntry * FE,bool WantExternal) const977 HeaderSearch::getExistingFileInfo(const FileEntry *FE,
978                                   bool WantExternal) const {
979   // If we have an external source, ensure we have the latest information.
980   // FIXME: Use a generation count to check whether this is really up to date.
981   HeaderFileInfo *HFI;
982   if (ExternalSource) {
983     if (FE->getUID() >= FileInfo.size()) {
984       if (!WantExternal)
985         return nullptr;
986       FileInfo.resize(FE->getUID() + 1);
987     }
988 
989     HFI = &FileInfo[FE->getUID()];
990     if (!WantExternal && (!HFI->IsValid || HFI->External))
991       return nullptr;
992     if (!HFI->Resolved) {
993       HFI->Resolved = true;
994       auto ExternalHFI = ExternalSource->GetHeaderFileInfo(FE);
995 
996       HFI = &FileInfo[FE->getUID()];
997       if (ExternalHFI.External)
998         mergeHeaderFileInfo(*HFI, ExternalHFI);
999     }
1000   } else if (FE->getUID() >= FileInfo.size()) {
1001     return nullptr;
1002   } else {
1003     HFI = &FileInfo[FE->getUID()];
1004   }
1005 
1006   if (!HFI->IsValid || (HFI->External && !WantExternal))
1007     return nullptr;
1008 
1009   return HFI;
1010 }
1011 
isFileMultipleIncludeGuarded(const FileEntry * File)1012 bool HeaderSearch::isFileMultipleIncludeGuarded(const FileEntry *File) {
1013   // Check if we've ever seen this file as a header.
1014   if (auto *HFI = getExistingFileInfo(File))
1015     return HFI->isPragmaOnce || HFI->isImport || HFI->ControllingMacro ||
1016            HFI->ControllingMacroID;
1017   return false;
1018 }
1019 
MarkFileModuleHeader(const FileEntry * FE,ModuleMap::ModuleHeaderRole Role,bool isCompilingModuleHeader)1020 void HeaderSearch::MarkFileModuleHeader(const FileEntry *FE,
1021                                         ModuleMap::ModuleHeaderRole Role,
1022                                         bool isCompilingModuleHeader) {
1023   bool isModularHeader = !(Role & ModuleMap::TextualHeader);
1024 
1025   // Don't mark the file info as non-external if there's nothing to change.
1026   if (!isCompilingModuleHeader) {
1027     if (!isModularHeader)
1028       return;
1029     auto *HFI = getExistingFileInfo(FE);
1030     if (HFI && HFI->isModuleHeader)
1031       return;
1032   }
1033 
1034   auto &HFI = getFileInfo(FE);
1035   HFI.isModuleHeader |= isModularHeader;
1036   HFI.isCompilingModuleHeader |= isCompilingModuleHeader;
1037 }
1038 
ShouldEnterIncludeFile(Preprocessor & PP,const FileEntry * File,bool isImport,Module * M)1039 bool HeaderSearch::ShouldEnterIncludeFile(Preprocessor &PP,
1040                                           const FileEntry *File,
1041                                           bool isImport, Module *M) {
1042   ++NumIncluded; // Count # of attempted #includes.
1043 
1044   // Get information about this file.
1045   HeaderFileInfo &FileInfo = getFileInfo(File);
1046 
1047   // If this is a #import directive, check that we have not already imported
1048   // this header.
1049   if (isImport) {
1050     // If this has already been imported, don't import it again.
1051     FileInfo.isImport = true;
1052 
1053     // Has this already been #import'ed or #include'd?
1054     if (FileInfo.NumIncludes) return false;
1055   } else {
1056     // Otherwise, if this is a #include of a file that was previously #import'd
1057     // or if this is the second #include of a #pragma once file, ignore it.
1058     if (FileInfo.isImport)
1059       return false;
1060   }
1061 
1062   // Next, check to see if the file is wrapped with #ifndef guards.  If so, and
1063   // if the macro that guards it is defined, we know the #include has no effect.
1064   if (const IdentifierInfo *ControllingMacro
1065       = FileInfo.getControllingMacro(ExternalLookup)) {
1066     // If the header corresponds to a module, check whether the macro is already
1067     // defined in that module rather than checking in the current set of visible
1068     // modules.
1069     if (M ? PP.isMacroDefinedInLocalModule(ControllingMacro, M)
1070           : PP.isMacroDefined(ControllingMacro)) {
1071       ++NumMultiIncludeFileOptzn;
1072       return false;
1073     }
1074   }
1075 
1076   // Increment the number of times this file has been included.
1077   ++FileInfo.NumIncludes;
1078 
1079   return true;
1080 }
1081 
getTotalMemory() const1082 size_t HeaderSearch::getTotalMemory() const {
1083   return SearchDirs.capacity()
1084     + llvm::capacity_in_bytes(FileInfo)
1085     + llvm::capacity_in_bytes(HeaderMaps)
1086     + LookupFileCache.getAllocator().getTotalMemory()
1087     + FrameworkMap.getAllocator().getTotalMemory();
1088 }
1089 
getUniqueFrameworkName(StringRef Framework)1090 StringRef HeaderSearch::getUniqueFrameworkName(StringRef Framework) {
1091   return FrameworkNames.insert(Framework).first->first();
1092 }
1093 
hasModuleMap(StringRef FileName,const DirectoryEntry * Root,bool IsSystem)1094 bool HeaderSearch::hasModuleMap(StringRef FileName,
1095                                 const DirectoryEntry *Root,
1096                                 bool IsSystem) {
1097   if (!HSOpts->ImplicitModuleMaps)
1098     return false;
1099 
1100   SmallVector<const DirectoryEntry *, 2> FixUpDirectories;
1101 
1102   StringRef DirName = FileName;
1103   do {
1104     // Get the parent directory name.
1105     DirName = llvm::sys::path::parent_path(DirName);
1106     if (DirName.empty())
1107       return false;
1108 
1109     // Determine whether this directory exists.
1110     const DirectoryEntry *Dir = FileMgr.getDirectory(DirName);
1111     if (!Dir)
1112       return false;
1113 
1114     // Try to load the module map file in this directory.
1115     switch (loadModuleMapFile(Dir, IsSystem,
1116                               llvm::sys::path::extension(Dir->getName()) ==
1117                                   ".framework")) {
1118     case LMM_NewlyLoaded:
1119     case LMM_AlreadyLoaded:
1120       // Success. All of the directories we stepped through inherit this module
1121       // map file.
1122       for (unsigned I = 0, N = FixUpDirectories.size(); I != N; ++I)
1123         DirectoryHasModuleMap[FixUpDirectories[I]] = true;
1124       return true;
1125 
1126     case LMM_NoDirectory:
1127     case LMM_InvalidModuleMap:
1128       break;
1129     }
1130 
1131     // If we hit the top of our search, we're done.
1132     if (Dir == Root)
1133       return false;
1134 
1135     // Keep track of all of the directories we checked, so we can mark them as
1136     // having module maps if we eventually do find a module map.
1137     FixUpDirectories.push_back(Dir);
1138   } while (true);
1139 }
1140 
1141 ModuleMap::KnownHeader
findModuleForHeader(const FileEntry * File) const1142 HeaderSearch::findModuleForHeader(const FileEntry *File) const {
1143   if (ExternalSource) {
1144     // Make sure the external source has handled header info about this file,
1145     // which includes whether the file is part of a module.
1146     (void)getExistingFileInfo(File);
1147   }
1148   return ModMap.findModuleForHeader(File);
1149 }
1150 
findUsableModuleForHeader(const FileEntry * File,const DirectoryEntry * Root,Module * RequestingModule,ModuleMap::KnownHeader * SuggestedModule,bool IsSystemHeaderDir)1151 bool HeaderSearch::findUsableModuleForHeader(
1152     const FileEntry *File, const DirectoryEntry *Root, Module *RequestingModule,
1153     ModuleMap::KnownHeader *SuggestedModule, bool IsSystemHeaderDir) {
1154   if (File && SuggestedModule) {
1155     // If there is a module that corresponds to this header, suggest it.
1156     hasModuleMap(File->getName(), Root, IsSystemHeaderDir);
1157     *SuggestedModule = findModuleForHeader(File);
1158   }
1159   return true;
1160 }
1161 
findUsableModuleForFrameworkHeader(const FileEntry * File,StringRef FrameworkName,Module * RequestingModule,ModuleMap::KnownHeader * SuggestedModule,bool IsSystemFramework)1162 bool HeaderSearch::findUsableModuleForFrameworkHeader(
1163     const FileEntry *File, StringRef FrameworkName, Module *RequestingModule,
1164     ModuleMap::KnownHeader *SuggestedModule, bool IsSystemFramework) {
1165   // If we're supposed to suggest a module, look for one now.
1166   if (SuggestedModule) {
1167     // Find the top-level framework based on this framework.
1168     SmallVector<std::string, 4> SubmodulePath;
1169     const DirectoryEntry *TopFrameworkDir
1170       = ::getTopFrameworkDir(FileMgr, FrameworkName, SubmodulePath);
1171 
1172     // Determine the name of the top-level framework.
1173     StringRef ModuleName = llvm::sys::path::stem(TopFrameworkDir->getName());
1174 
1175     // Load this framework module. If that succeeds, find the suggested module
1176     // for this header, if any.
1177     loadFrameworkModule(ModuleName, TopFrameworkDir, IsSystemFramework);
1178 
1179     // FIXME: This can find a module not part of ModuleName, which is
1180     // important so that we're consistent about whether this header
1181     // corresponds to a module. Possibly we should lock down framework modules
1182     // so that this is not possible.
1183     *SuggestedModule = findModuleForHeader(File);
1184   }
1185   return true;
1186 }
1187 
getPrivateModuleMap(const FileEntry * File,FileManager & FileMgr)1188 static const FileEntry *getPrivateModuleMap(const FileEntry *File,
1189                                             FileManager &FileMgr) {
1190   StringRef Filename = llvm::sys::path::filename(File->getName());
1191   SmallString<128>  PrivateFilename(File->getDir()->getName());
1192   if (Filename == "module.map")
1193     llvm::sys::path::append(PrivateFilename, "module_private.map");
1194   else if (Filename == "module.modulemap")
1195     llvm::sys::path::append(PrivateFilename, "module.private.modulemap");
1196   else
1197     return nullptr;
1198   return FileMgr.getFile(PrivateFilename);
1199 }
1200 
loadModuleMapFile(const FileEntry * File,bool IsSystem)1201 bool HeaderSearch::loadModuleMapFile(const FileEntry *File, bool IsSystem) {
1202   // Find the directory for the module. For frameworks, that may require going
1203   // up from the 'Modules' directory.
1204   const DirectoryEntry *Dir = nullptr;
1205   if (getHeaderSearchOpts().ModuleMapFileHomeIsCwd)
1206     Dir = FileMgr.getDirectory(".");
1207   else {
1208     Dir = File->getDir();
1209     StringRef DirName(Dir->getName());
1210     if (llvm::sys::path::filename(DirName) == "Modules") {
1211       DirName = llvm::sys::path::parent_path(DirName);
1212       if (DirName.endswith(".framework"))
1213         Dir = FileMgr.getDirectory(DirName);
1214       // FIXME: This assert can fail if there's a race between the above check
1215       // and the removal of the directory.
1216       assert(Dir && "parent must exist");
1217     }
1218   }
1219 
1220   switch (loadModuleMapFileImpl(File, IsSystem, Dir)) {
1221   case LMM_AlreadyLoaded:
1222   case LMM_NewlyLoaded:
1223     return false;
1224   case LMM_NoDirectory:
1225   case LMM_InvalidModuleMap:
1226     return true;
1227   }
1228   llvm_unreachable("Unknown load module map result");
1229 }
1230 
1231 HeaderSearch::LoadModuleMapResult
loadModuleMapFileImpl(const FileEntry * File,bool IsSystem,const DirectoryEntry * Dir)1232 HeaderSearch::loadModuleMapFileImpl(const FileEntry *File, bool IsSystem,
1233                                     const DirectoryEntry *Dir) {
1234   assert(File && "expected FileEntry");
1235 
1236   // Check whether we've already loaded this module map, and mark it as being
1237   // loaded in case we recursively try to load it from itself.
1238   auto AddResult = LoadedModuleMaps.insert(std::make_pair(File, true));
1239   if (!AddResult.second)
1240     return AddResult.first->second ? LMM_AlreadyLoaded : LMM_InvalidModuleMap;
1241 
1242   if (ModMap.parseModuleMapFile(File, IsSystem, Dir)) {
1243     LoadedModuleMaps[File] = false;
1244     return LMM_InvalidModuleMap;
1245   }
1246 
1247   // Try to load a corresponding private module map.
1248   if (const FileEntry *PMMFile = getPrivateModuleMap(File, FileMgr)) {
1249     if (ModMap.parseModuleMapFile(PMMFile, IsSystem, Dir)) {
1250       LoadedModuleMaps[File] = false;
1251       return LMM_InvalidModuleMap;
1252     }
1253   }
1254 
1255   // This directory has a module map.
1256   return LMM_NewlyLoaded;
1257 }
1258 
1259 const FileEntry *
lookupModuleMapFile(const DirectoryEntry * Dir,bool IsFramework)1260 HeaderSearch::lookupModuleMapFile(const DirectoryEntry *Dir, bool IsFramework) {
1261   if (!HSOpts->ImplicitModuleMaps)
1262     return nullptr;
1263   // For frameworks, the preferred spelling is Modules/module.modulemap, but
1264   // module.map at the framework root is also accepted.
1265   SmallString<128> ModuleMapFileName(Dir->getName());
1266   if (IsFramework)
1267     llvm::sys::path::append(ModuleMapFileName, "Modules");
1268   llvm::sys::path::append(ModuleMapFileName, "module.modulemap");
1269   if (const FileEntry *F = FileMgr.getFile(ModuleMapFileName))
1270     return F;
1271 
1272   // Continue to allow module.map
1273   ModuleMapFileName = Dir->getName();
1274   llvm::sys::path::append(ModuleMapFileName, "module.map");
1275   return FileMgr.getFile(ModuleMapFileName);
1276 }
1277 
loadFrameworkModule(StringRef Name,const DirectoryEntry * Dir,bool IsSystem)1278 Module *HeaderSearch::loadFrameworkModule(StringRef Name,
1279                                           const DirectoryEntry *Dir,
1280                                           bool IsSystem) {
1281   if (Module *Module = ModMap.findModule(Name))
1282     return Module;
1283 
1284   // Try to load a module map file.
1285   switch (loadModuleMapFile(Dir, IsSystem, /*IsFramework*/true)) {
1286   case LMM_InvalidModuleMap:
1287     // Try to infer a module map from the framework directory.
1288     if (HSOpts->ImplicitModuleMaps)
1289       ModMap.inferFrameworkModule(Dir, IsSystem, /*Parent=*/nullptr);
1290     break;
1291 
1292   case LMM_AlreadyLoaded:
1293   case LMM_NoDirectory:
1294     return nullptr;
1295 
1296   case LMM_NewlyLoaded:
1297     break;
1298   }
1299 
1300   return ModMap.findModule(Name);
1301 }
1302 
1303 
1304 HeaderSearch::LoadModuleMapResult
loadModuleMapFile(StringRef DirName,bool IsSystem,bool IsFramework)1305 HeaderSearch::loadModuleMapFile(StringRef DirName, bool IsSystem,
1306                                 bool IsFramework) {
1307   if (const DirectoryEntry *Dir = FileMgr.getDirectory(DirName))
1308     return loadModuleMapFile(Dir, IsSystem, IsFramework);
1309 
1310   return LMM_NoDirectory;
1311 }
1312 
1313 HeaderSearch::LoadModuleMapResult
loadModuleMapFile(const DirectoryEntry * Dir,bool IsSystem,bool IsFramework)1314 HeaderSearch::loadModuleMapFile(const DirectoryEntry *Dir, bool IsSystem,
1315                                 bool IsFramework) {
1316   auto KnownDir = DirectoryHasModuleMap.find(Dir);
1317   if (KnownDir != DirectoryHasModuleMap.end())
1318     return KnownDir->second ? LMM_AlreadyLoaded : LMM_InvalidModuleMap;
1319 
1320   if (const FileEntry *ModuleMapFile = lookupModuleMapFile(Dir, IsFramework)) {
1321     LoadModuleMapResult Result =
1322         loadModuleMapFileImpl(ModuleMapFile, IsSystem, Dir);
1323     // Add Dir explicitly in case ModuleMapFile is in a subdirectory.
1324     // E.g. Foo.framework/Modules/module.modulemap
1325     //      ^Dir                  ^ModuleMapFile
1326     if (Result == LMM_NewlyLoaded)
1327       DirectoryHasModuleMap[Dir] = true;
1328     else if (Result == LMM_InvalidModuleMap)
1329       DirectoryHasModuleMap[Dir] = false;
1330     return Result;
1331   }
1332   return LMM_InvalidModuleMap;
1333 }
1334 
collectAllModules(SmallVectorImpl<Module * > & Modules)1335 void HeaderSearch::collectAllModules(SmallVectorImpl<Module *> &Modules) {
1336   Modules.clear();
1337 
1338   if (HSOpts->ImplicitModuleMaps) {
1339     // Load module maps for each of the header search directories.
1340     for (unsigned Idx = 0, N = SearchDirs.size(); Idx != N; ++Idx) {
1341       bool IsSystem = SearchDirs[Idx].isSystemHeaderDirectory();
1342       if (SearchDirs[Idx].isFramework()) {
1343         std::error_code EC;
1344         SmallString<128> DirNative;
1345         llvm::sys::path::native(SearchDirs[Idx].getFrameworkDir()->getName(),
1346                                 DirNative);
1347 
1348         // Search each of the ".framework" directories to load them as modules.
1349         vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
1350         for (vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC), DirEnd;
1351              Dir != DirEnd && !EC; Dir.increment(EC)) {
1352           if (llvm::sys::path::extension(Dir->getName()) != ".framework")
1353             continue;
1354 
1355           const DirectoryEntry *FrameworkDir =
1356               FileMgr.getDirectory(Dir->getName());
1357           if (!FrameworkDir)
1358             continue;
1359 
1360           // Load this framework module.
1361           loadFrameworkModule(llvm::sys::path::stem(Dir->getName()),
1362                               FrameworkDir, IsSystem);
1363         }
1364         continue;
1365       }
1366 
1367       // FIXME: Deal with header maps.
1368       if (SearchDirs[Idx].isHeaderMap())
1369         continue;
1370 
1371       // Try to load a module map file for the search directory.
1372       loadModuleMapFile(SearchDirs[Idx].getDir(), IsSystem,
1373                         /*IsFramework*/ false);
1374 
1375       // Try to load module map files for immediate subdirectories of this
1376       // search directory.
1377       loadSubdirectoryModuleMaps(SearchDirs[Idx]);
1378     }
1379   }
1380 
1381   // Populate the list of modules.
1382   for (ModuleMap::module_iterator M = ModMap.module_begin(),
1383                                MEnd = ModMap.module_end();
1384        M != MEnd; ++M) {
1385     Modules.push_back(M->getValue());
1386   }
1387 }
1388 
loadTopLevelSystemModules()1389 void HeaderSearch::loadTopLevelSystemModules() {
1390   if (!HSOpts->ImplicitModuleMaps)
1391     return;
1392 
1393   // Load module maps for each of the header search directories.
1394   for (unsigned Idx = 0, N = SearchDirs.size(); Idx != N; ++Idx) {
1395     // We only care about normal header directories.
1396     if (!SearchDirs[Idx].isNormalDir()) {
1397       continue;
1398     }
1399 
1400     // Try to load a module map file for the search directory.
1401     loadModuleMapFile(SearchDirs[Idx].getDir(),
1402                       SearchDirs[Idx].isSystemHeaderDirectory(),
1403                       SearchDirs[Idx].isFramework());
1404   }
1405 }
1406 
loadSubdirectoryModuleMaps(DirectoryLookup & SearchDir)1407 void HeaderSearch::loadSubdirectoryModuleMaps(DirectoryLookup &SearchDir) {
1408   assert(HSOpts->ImplicitModuleMaps &&
1409          "Should not be loading subdirectory module maps");
1410 
1411   if (SearchDir.haveSearchedAllModuleMaps())
1412     return;
1413 
1414   std::error_code EC;
1415   SmallString<128> DirNative;
1416   llvm::sys::path::native(SearchDir.getDir()->getName(), DirNative);
1417   vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
1418   for (vfs::directory_iterator Dir = FS.dir_begin(DirNative, EC), DirEnd;
1419        Dir != DirEnd && !EC; Dir.increment(EC)) {
1420     bool IsFramework =
1421         llvm::sys::path::extension(Dir->getName()) == ".framework";
1422     if (IsFramework == SearchDir.isFramework())
1423       loadModuleMapFile(Dir->getName(), SearchDir.isSystemHeaderDirectory(),
1424                         SearchDir.isFramework());
1425   }
1426 
1427   SearchDir.setSearchedAllModuleMaps(true);
1428 }
1429 
suggestPathToFileForDiagnostics(const FileEntry * File,bool * IsSystem)1430 std::string HeaderSearch::suggestPathToFileForDiagnostics(const FileEntry *File,
1431                                                           bool *IsSystem) {
1432   // FIXME: We assume that the path name currently cached in the FileEntry is
1433   // the most appropriate one for this analysis (and that it's spelled the same
1434   // way as the corresponding header search path).
1435   const char *Name = File->getName();
1436 
1437   unsigned BestPrefixLength = 0;
1438   unsigned BestSearchDir;
1439 
1440   for (unsigned I = 0; I != SearchDirs.size(); ++I) {
1441     // FIXME: Support this search within frameworks and header maps.
1442     if (!SearchDirs[I].isNormalDir())
1443       continue;
1444 
1445     const char *Dir = SearchDirs[I].getDir()->getName();
1446     for (auto NI = llvm::sys::path::begin(Name),
1447               NE = llvm::sys::path::end(Name),
1448               DI = llvm::sys::path::begin(Dir),
1449               DE = llvm::sys::path::end(Dir);
1450          /*termination condition in loop*/; ++NI, ++DI) {
1451       // '.' components in Name are ignored.
1452       while (NI != NE && *NI == ".")
1453         ++NI;
1454       if (NI == NE)
1455         break;
1456 
1457       // '.' components in Dir are ignored.
1458       while (DI != DE && *DI == ".")
1459         ++DI;
1460       if (DI == DE) {
1461         // Dir is a prefix of Name, up to '.' components and choice of path
1462         // separators.
1463         unsigned PrefixLength = NI - llvm::sys::path::begin(Name);
1464         if (PrefixLength > BestPrefixLength) {
1465           BestPrefixLength = PrefixLength;
1466           BestSearchDir = I;
1467         }
1468         break;
1469       }
1470 
1471       if (*NI != *DI)
1472         break;
1473     }
1474   }
1475 
1476   if (IsSystem)
1477     *IsSystem = BestPrefixLength ? BestSearchDir >= SystemDirIdx : false;
1478   return Name + BestPrefixLength;
1479 }
1480