Add the clang library to the repo (with some of my changes, too).

1 files changed, 1035 insertions, 0 deletions

diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp
new file mode 100644
index 0000000..d688e23
--- /dev/null
+++ b/clang/lib/Lex/HeaderSearch.cpp
@@ -0,0 +1,1035 @@
+//===--- HeaderSearch.cpp - Resolve Header File Locations ---===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file implements the DirectoryLookup and HeaderSearch interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Lex/HeaderSearch.h"
+#include "clang/Lex/HeaderMap.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/FileManager.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/Capacity.h"
+#include <cstdio>
+using namespace clang;
+
+const IdentifierInfo *
+HeaderFileInfo::getControllingMacro(ExternalIdentifierLookup *External) {
+  if (ControllingMacro)
+    return ControllingMacro;
+
+  if (!ControllingMacroID || !External)
+    return 0;
+
+  ControllingMacro = External->GetIdentifier(ControllingMacroID);
+  return ControllingMacro;
+}
+
+ExternalHeaderFileInfoSource::~ExternalHeaderFileInfoSource() {}
+
+HeaderSearch::HeaderSearch(FileManager &FM, DiagnosticsEngine &Diags,
+                           const LangOptions &LangOpts, 
+                           const TargetInfo *Target)
+  : FileMgr(FM), Diags(Diags), FrameworkMap(64), 
+    ModMap(FileMgr, *Diags.getClient(), LangOpts, Target)
+{
+  AngledDirIdx = 0;
+  SystemDirIdx = 0;
+  NoCurDirSearch = false;
+
+  ExternalLookup = 0;
+  ExternalSource = 0;
+  NumIncluded = 0;
+  NumMultiIncludeFileOptzn = 0;
+  NumFrameworkLookups = NumSubFrameworkLookups = 0;
+}
+
+HeaderSearch::~HeaderSearch() {
+  // Delete headermaps.
+  for (unsigned i = 0, e = HeaderMaps.size(); i != e; ++i)
+    delete HeaderMaps[i].second;
+}
+
+void HeaderSearch::PrintStats() {
+  fprintf(stderr, "\n*** HeaderSearch Stats:\n");
+  fprintf(stderr, "%d files tracked.\n", (int)FileInfo.size());
+  unsigned NumOnceOnlyFiles = 0, MaxNumIncludes = 0, NumSingleIncludedFiles = 0;
+  for (unsigned i = 0, e = FileInfo.size(); i != e; ++i) {
+    NumOnceOnlyFiles += FileInfo[i].isImport;
+    if (MaxNumIncludes < FileInfo[i].NumIncludes)
+      MaxNumIncludes = FileInfo[i].NumIncludes;
+    NumSingleIncludedFiles += FileInfo[i].NumIncludes == 1;
+  }
+  fprintf(stderr, "  %d #import/#pragma once files.\n", NumOnceOnlyFiles);
+  fprintf(stderr, "  %d included exactly once.\n", NumSingleIncludedFiles);
+  fprintf(stderr, "  %d max times a file is included.\n", MaxNumIncludes);
+
+  fprintf(stderr, "  %d #include/#include_next/#import.\n", NumIncluded);
+  fprintf(stderr, "    %d #includes skipped due to"
+          " the multi-include optimization.\n", NumMultiIncludeFileOptzn);
+
+  fprintf(stderr, "%d framework lookups.\n", NumFrameworkLookups);
+  fprintf(stderr, "%d subframework lookups.\n", NumSubFrameworkLookups);
+}
+
+/// CreateHeaderMap - This method returns a HeaderMap for the specified
+/// FileEntry, uniquing them through the the 'HeaderMaps' datastructure.
+const HeaderMap *HeaderSearch::CreateHeaderMap(const FileEntry *FE) {
+  // We expect the number of headermaps to be small, and almost always empty.
+  // If it ever grows, use of a linear search should be re-evaluated.
+  if (!HeaderMaps.empty()) {
+    for (unsigned i = 0, e = HeaderMaps.size(); i != e; ++i)
+      // Pointer equality comparison of FileEntries works because they are
+      // already uniqued by inode.
+      if (HeaderMaps[i].first == FE)
+        return HeaderMaps[i].second;
+  }
+
+  if (const HeaderMap *HM = HeaderMap::Create(FE, FileMgr)) {
+    HeaderMaps.push_back(std::make_pair(FE, HM));
+    return HM;
+  }
+
+  return 0;
+}
+
+std::string HeaderSearch::getModuleFileName(Module *Module) {
+  // If we don't have a module cache path, we can't do anything.
+  if (ModuleCachePath.empty()) 
+    return std::string();
+
+
+  SmallString<256> Result(ModuleCachePath);
+  llvm::sys::path::append(Result, Module->getTopLevelModule()->Name + ".pcm");
+  return Result.str().str();
+}
+
+std::string HeaderSearch::getModuleFileName(StringRef ModuleName) {
+  // If we don't have a module cache path, we can't do anything.
+  if (ModuleCachePath.empty()) 
+    return std::string();
+  
+  
+  SmallString<256> Result(ModuleCachePath);
+  llvm::sys::path::append(Result, ModuleName + ".pcm");
+  return Result.str().str();
+}
+
+Module *HeaderSearch::lookupModule(StringRef ModuleName, bool AllowSearch) {
+  // Look in the module map to determine if there is a module by this name.
+  Module *Module = ModMap.findModule(ModuleName);
+  if (Module || !AllowSearch)
+    return Module;
+  
+  // Look through the various header search paths to load any avai;able module 
+  // maps, searching for a module map that describes this module.
+  for (unsigned Idx = 0, N = SearchDirs.size(); Idx != N; ++Idx) {
+    if (SearchDirs[Idx].isFramework()) {
+      // Search for or infer a module map for a framework.
+      SmallString<128> FrameworkDirName;
+      FrameworkDirName += SearchDirs[Idx].getFrameworkDir()->getName();
+      llvm::sys::path::append(FrameworkDirName, ModuleName + ".framework");
+      if (const DirectoryEntry *FrameworkDir 
+            = FileMgr.getDirectory(FrameworkDirName)) {
+        bool IsSystem
+          = SearchDirs[Idx].getDirCharacteristic() != SrcMgr::C_User;
+        Module = loadFrameworkModule(ModuleName, FrameworkDir, IsSystem);
+        if (Module)
+          break;
+      }
+    }
+    
+    // FIXME: Figure out how header maps and module maps will work together.
+    
+    // Only deal with normal search directories.
+    if (!SearchDirs[Idx].isNormalDir())
+      continue;
+    
+    // Search for a module map file in this directory.
+    if (loadModuleMapFile(SearchDirs[Idx].getDir()) == LMM_NewlyLoaded) {
+      // We just loaded a module map file; check whether the module is
+      // available now.
+      Module = ModMap.findModule(ModuleName);
+      if (Module)
+        break;
+    }
+              
+    // Search for a module map in a subdirectory with the same name as the
+    // module.
+    SmallString<128> NestedModuleMapDirName;
+    NestedModuleMapDirName = SearchDirs[Idx].getDir()->getName();
+    llvm::sys::path::append(NestedModuleMapDirName, ModuleName);
+    if (loadModuleMapFile(NestedModuleMapDirName) == LMM_NewlyLoaded) {
+      // If we just loaded a module map file, look for the module again.
+      Module = ModMap.findModule(ModuleName);
+      if (Module)
+        break;
+    }
+  }
+  
+  return Module;
+}
+
+//===----------------------------------------------------------------------===//
+// File lookup within a DirectoryLookup scope
+//===----------------------------------------------------------------------===//
+
+/// getName - Return the directory or filename corresponding to this lookup
+/// object.
+const char *DirectoryLookup::getName() const {
+  if (isNormalDir())
+    return getDir()->getName();
+  if (isFramework())
+    return getFrameworkDir()->getName();
+  assert(isHeaderMap() && "Unknown DirectoryLookup");
+  return getHeaderMap()->getFileName();
+}
+
+
+/// LookupFile - Lookup the specified file in this search path, returning it
+/// if it exists or returning null if not.
+const FileEntry *DirectoryLookup::LookupFile(
+    StringRef Filename,
+    HeaderSearch &HS,
+    SmallVectorImpl<char> *SearchPath,
+    SmallVectorImpl<char> *RelativePath,
+    Module **SuggestedModule,
+    bool &InUserSpecifiedSystemFramework) const {
+  InUserSpecifiedSystemFramework = false;
+
+  SmallString<1024> TmpDir;
+  if (isNormalDir()) {
+    // Concatenate the requested file onto the directory.
+    TmpDir = getDir()->getName();
+    llvm::sys::path::append(TmpDir, Filename);
+    if (SearchPath != NULL) {
+      StringRef SearchPathRef(getDir()->getName());
+      SearchPath->clear();
+      SearchPath->append(SearchPathRef.begin(), SearchPathRef.end());
+    }
+    if (RelativePath != NULL) {
+      RelativePath->clear();
+      RelativePath->append(Filename.begin(), Filename.end());
+    }
+    
+    // If we have a module map that might map this header, load it and
+    // check whether we'll have a suggestion for a module.
+    if (SuggestedModule && HS.hasModuleMap(TmpDir, getDir())) {
+      const FileEntry *File = HS.getFileMgr().getFile(TmpDir.str(), 
+                                                      /*openFile=*/false);
+      if (!File)
+        return File;
+      
+      // If there is a module that corresponds to this header, 
+      // suggest it.
+      *SuggestedModule = HS.findModuleForHeader(File);
+      return File;
+    }
+    
+    return HS.getFileMgr().getFile(TmpDir.str(), /*openFile=*/true);
+  }
+
+  if (isFramework())
+    return DoFrameworkLookup(Filename, HS, SearchPath, RelativePath,
+                             SuggestedModule, InUserSpecifiedSystemFramework);
+
+  assert(isHeaderMap() && "Unknown directory lookup");
+  const FileEntry * const Result = getHeaderMap()->LookupFile(
+      Filename, HS.getFileMgr());
+  if (Result) {
+    if (SearchPath != NULL) {
+      StringRef SearchPathRef(getName());
+      SearchPath->clear();
+      SearchPath->append(SearchPathRef.begin(), SearchPathRef.end());
+    }
+    if (RelativePath != NULL) {
+      RelativePath->clear();
+      RelativePath->append(Filename.begin(), Filename.end());
+    }
+  }
+  return Result;
+}
+
+
+/// DoFrameworkLookup - Do a lookup of the specified file in the current
+/// DirectoryLookup, which is a framework directory.
+const FileEntry *DirectoryLookup::DoFrameworkLookup(
+    StringRef Filename,
+    HeaderSearch &HS,
+    SmallVectorImpl<char> *SearchPath,
+    SmallVectorImpl<char> *RelativePath,
+    Module **SuggestedModule,
+    bool &InUserSpecifiedSystemFramework) const
+{
+  FileManager &FileMgr = HS.getFileMgr();
+
+  // Framework names must have a '/' in the filename.
+  size_t SlashPos = Filename.find('/');
+  if (SlashPos == StringRef::npos) return 0;
+
+  // Find out if this is the home for the specified framework, by checking
+  // HeaderSearch.  Possible answers are yes/no and unknown.
+  HeaderSearch::FrameworkCacheEntry &CacheEntry =
+    HS.LookupFrameworkCache(Filename.substr(0, SlashPos));
+
+  // If it is known and in some other directory, fail.
+  if (CacheEntry.Directory && CacheEntry.Directory != getFrameworkDir())
+    return 0;
+
+  // Otherwise, construct the path to this framework dir.
+
+  // FrameworkName = "/System/Library/Frameworks/"
+  SmallString<1024> FrameworkName;
+  FrameworkName += getFrameworkDir()->getName();
+  if (FrameworkName.empty() || FrameworkName.back() != '/')
+    FrameworkName.push_back('/');
+
+  // FrameworkName = "/System/Library/Frameworks/Cocoa"
+  StringRef ModuleName(Filename.begin(), SlashPos);
+  FrameworkName += ModuleName;
+
+  // FrameworkName = "/System/Library/Frameworks/Cocoa.framework/"
+  FrameworkName += ".framework/";
+
+  // If the cache entry was unresolved, populate it now.
+  if (CacheEntry.Directory == 0) {
+    HS.IncrementFrameworkLookupCount();
+
+    // If the framework dir doesn't exist, we fail.
+    const DirectoryEntry *Dir = FileMgr.getDirectory(FrameworkName.str());
+    if (Dir == 0) return 0;
+
+    // Otherwise, if it does, remember that this is the right direntry for this
+    // framework.
+    CacheEntry.Directory = getFrameworkDir();
+
+    // If this is a user search directory, check if the framework has been
+    // user-specified as a system framework.
+    if (getDirCharacteristic() == SrcMgr::C_User) {
+      SmallString<1024> SystemFrameworkMarker(FrameworkName);
+      SystemFrameworkMarker += ".system_framework";
+      if (llvm::sys::fs::exists(SystemFrameworkMarker.str())) {
+        CacheEntry.IsUserSpecifiedSystemFramework = true;
+      }
+    }
+  }
+
+  // Set the 'user-specified system framework' flag.
+  InUserSpecifiedSystemFramework = CacheEntry.IsUserSpecifiedSystemFramework;
+
+  if (RelativePath != NULL) {
+    RelativePath->clear();
+    RelativePath->append(Filename.begin()+SlashPos+1, Filename.end());
+  }
+
+  // If we're allowed to look for modules, try to load or create the module
+  // corresponding to this framework.
+  Module *Module = 0;
+  if (SuggestedModule) {
+    if (const DirectoryEntry *FrameworkDir
+                                        = FileMgr.getDirectory(FrameworkName)) {
+      bool IsSystem = getDirCharacteristic() != SrcMgr::C_User;
+      Module = HS.loadFrameworkModule(ModuleName, FrameworkDir, IsSystem);
+    }
+  }
+  
+  // Check "/System/Library/Frameworks/Cocoa.framework/Headers/file.h"
+  unsigned OrigSize = FrameworkName.size();
+
+  FrameworkName += "Headers/";
+
+  if (SearchPath != NULL) {
+    SearchPath->clear();
+    // Without trailing '/'.
+    SearchPath->append(FrameworkName.begin(), FrameworkName.end()-1);
+  }
+
+  // Determine whether this is the module we're building or not.
+  bool AutomaticImport = Module;  
+  FrameworkName.append(Filename.begin()+SlashPos+1, Filename.end());
+  if (const FileEntry *FE = FileMgr.getFile(FrameworkName.str(),
+                                            /*openFile=*/!AutomaticImport)) {
+    if (AutomaticImport)
+      *SuggestedModule = HS.findModuleForHeader(FE);
+    return FE;
+  }
+
+  // Check "/System/Library/Frameworks/Cocoa.framework/PrivateHeaders/file.h"
+  const char *Private = "Private";
+  FrameworkName.insert(FrameworkName.begin()+OrigSize, Private,
+                       Private+strlen(Private));
+  if (SearchPath != NULL)
+    SearchPath->insert(SearchPath->begin()+OrigSize, Private,
+                       Private+strlen(Private));
+
+  const FileEntry *FE = FileMgr.getFile(FrameworkName.str(), 
+                                        /*openFile=*/!AutomaticImport);
+  if (FE && AutomaticImport)
+    *SuggestedModule = HS.findModuleForHeader(FE);
+  return FE;
+}
+
+void HeaderSearch::setTarget(const TargetInfo &Target) {
+  ModMap.setTarget(Target);
+}
+
+
+//===----------------------------------------------------------------------===//
+// Header File Location.
+//===----------------------------------------------------------------------===//
+
+
+/// LookupFile - Given a "foo" or <foo> reference, look up the indicated file,
+/// return null on failure.  isAngled indicates whether the file reference is
+/// for system #include's or not (i.e. using <> instead of "").  CurFileEnt, if
+/// non-null, indicates where the #including file is, in case a relative search
+/// is needed.
+const FileEntry *HeaderSearch::LookupFile(
+    StringRef Filename,
+    bool isAngled,
+    const DirectoryLookup *FromDir,
+    const DirectoryLookup *&CurDir,
+    const FileEntry *CurFileEnt,
+    SmallVectorImpl<char> *SearchPath,
+    SmallVectorImpl<char> *RelativePath,
+    Module **SuggestedModule,
+    bool SkipCache)
+{
+  if (SuggestedModule)
+    *SuggestedModule = 0;
+    
+  // If 'Filename' is absolute, check to see if it exists and no searching.
+  if (llvm::sys::path::is_absolute(Filename)) {
+    CurDir = 0;
+
+    // If this was an #include_next "/absolute/file", fail.
+    if (FromDir) return 0;
+
+    if (SearchPath != NULL)
+      SearchPath->clear();
+    if (RelativePath != NULL) {
+      RelativePath->clear();
+      RelativePath->append(Filename.begin(), Filename.end());
+    }
+    // Otherwise, just return the file.
+    return FileMgr.getFile(Filename, /*openFile=*/true);
+  }
+
+  // Unless disabled, check to see if the file is in the #includer's
+  // directory.  This has to be based on CurFileEnt, not CurDir, because
+  // CurFileEnt could be a #include of a subdirectory (#include "foo/bar.h") and
+  // a subsequent include of "baz.h" should resolve to "whatever/foo/baz.h".
+  // This search is not done for <> headers.
+  if (CurFileEnt && !isAngled && !NoCurDirSearch) {
+    SmallString<1024> TmpDir;
+    // Concatenate the requested file onto the directory.
+    // FIXME: Portability.  Filename concatenation should be in sys::Path.
+    TmpDir += CurFileEnt->getDir()->getName();
+    TmpDir.push_back('/');
+    TmpDir.append(Filename.begin(), Filename.end());
+    if (const FileEntry *FE = FileMgr.getFile(TmpDir.str(),/*openFile=*/true)) {
+      // Leave CurDir unset.
+      // This file is a system header or C++ unfriendly if the old file is.
+      //
+      // Note that the temporary 'DirInfo' is required here, as either call to
+      // getFileInfo could resize the vector and we don't want to rely on order
+      // of evaluation.
+      unsigned DirInfo = getFileInfo(CurFileEnt).DirInfo;
+      getFileInfo(FE).DirInfo = DirInfo;
+      if (SearchPath != NULL) {
+        StringRef SearchPathRef(CurFileEnt->getDir()->getName());
+        SearchPath->clear();
+        SearchPath->append(SearchPathRef.begin(), SearchPathRef.end());
+      }
+      if (RelativePath != NULL) {
+        RelativePath->clear();
+        RelativePath->append(Filename.begin(), Filename.end());
+      }
+      return FE;
+    }
+  }
+
+  CurDir = 0;
+
+  // If this is a system #include, ignore the user #include locs.
+  unsigned i = isAngled ? AngledDirIdx : 0;
+
+  // If this is a #include_next request, start searching after the directory the
+  // file was found in.
+  if (FromDir)
+    i = FromDir-&SearchDirs[0];
+
+  // Cache all of the lookups performed by this method.  Many headers are
+  // multiply included, and the "pragma once" optimization prevents them from
+  // being relex/pp'd, but they would still have to search through a
+  // (potentially huge) series of SearchDirs to find it.
+  std::pair<unsigned, unsigned> &CacheLookup =
+    LookupFileCache.GetOrCreateValue(Filename).getValue();
+
+  // If the entry has been previously looked up, the first value will be
+  // non-zero.  If the value is equal to i (the start point of our search), then
+  // this is a matching hit.
+  if (!SkipCache && CacheLookup.first == i+1) {
+    // Skip querying potentially lots of directories for this lookup.
+    i = CacheLookup.second;
+  } else {
+    // Otherwise, this is the first query, or the previous query didn't match
+    // our search start.  We will fill in our found location below, so prime the
+    // start point value.
+    CacheLookup.first = i+1;
+  }
+
+  // Check each directory in sequence to see if it contains this file.
+  for (; i != SearchDirs.size(); ++i) {
+    bool InUserSpecifiedSystemFramework = false;
+    const FileEntry *FE =
+      SearchDirs[i].LookupFile(Filename, *this, SearchPath, RelativePath,
+                               SuggestedModule, InUserSpecifiedSystemFramework);
+    if (!FE) continue;
+
+    CurDir = &SearchDirs[i];
+
+    // This file is a system header or C++ unfriendly if the dir is.
+    HeaderFileInfo &HFI = getFileInfo(FE);
+    HFI.DirInfo = CurDir->getDirCharacteristic();
+
+    // If the directory characteristic is User but this framework was
+    // user-specified to be treated as a system framework, promote the
+    // characteristic.
+    if (HFI.DirInfo == SrcMgr::C_User && InUserSpecifiedSystemFramework)
+      HFI.DirInfo = SrcMgr::C_System;
+
+    // If this file is found in a header map and uses the framework style of
+    // includes, then this header is part of a framework we're building.
+    if (CurDir->isIndexHeaderMap()) {
+      size_t SlashPos = Filename.find('/');
+      if (SlashPos != StringRef::npos) {
+        HFI.IndexHeaderMapHeader = 1;
+        HFI.Framework = getUniqueFrameworkName(StringRef(Filename.begin(), 
+                                                         SlashPos));
+      }
+    }
+    
+    // Remember this location for the next lookup we do.
+    CacheLookup.second = i;
+    return FE;
+  }
+
+  // If we are including a file with a quoted include "foo.h" from inside
+  // a header in a framework that is currently being built, and we couldn't
+  // resolve "foo.h" any other way, change the include to <Foo/foo.h>, where
+  // "Foo" is the name of the framework in which the including header was found.
+  if (CurFileEnt && !isAngled && Filename.find('/') == StringRef::npos) {
+    HeaderFileInfo &IncludingHFI = getFileInfo(CurFileEnt);
+    if (IncludingHFI.IndexHeaderMapHeader) {
+      SmallString<128> ScratchFilename;
+      ScratchFilename += IncludingHFI.Framework;
+      ScratchFilename += '/';
+      ScratchFilename += Filename;
+      
+      const FileEntry *Result = LookupFile(ScratchFilename, /*isAngled=*/true,
+                                           FromDir, CurDir, CurFileEnt, 
+                                           SearchPath, RelativePath,
+                                           SuggestedModule);
+      std::pair<unsigned, unsigned> &CacheLookup 
+        = LookupFileCache.GetOrCreateValue(Filename).getValue();
+      CacheLookup.second
+        = LookupFileCache.GetOrCreateValue(ScratchFilename).getValue().second;
+      return Result;
+    }
+  }
+
+  // Otherwise, didn't find it. Remember we didn't find this.
+  CacheLookup.second = SearchDirs.size();
+  return 0;
+}
+
+/// LookupSubframeworkHeader - Look up a subframework for the specified
+/// #include file.  For example, if #include'ing <HIToolbox/HIToolbox.h> from
+/// within ".../Carbon.framework/Headers/Carbon.h", check to see if HIToolbox
+/// is a subframework within Carbon.framework.  If so, return the FileEntry
+/// for the designated file, otherwise return null.
+const FileEntry *HeaderSearch::
+LookupSubframeworkHeader(StringRef Filename,
+                         const FileEntry *ContextFileEnt,
+                         SmallVectorImpl<char> *SearchPath,
+                         SmallVectorImpl<char> *RelativePath) {
+  assert(ContextFileEnt && "No context file?");
+
+  // Framework names must have a '/' in the filename.  Find it.
+  // FIXME: Should we permit '\' on Windows?
+  size_t SlashPos = Filename.find('/');
+  if (SlashPos == StringRef::npos) return 0;
+
+  // Look up the base framework name of the ContextFileEnt.
+  const char *ContextName = ContextFileEnt->getName();
+
+  // If the context info wasn't a framework, couldn't be a subframework.
+  const unsigned DotFrameworkLen = 10;
+  const char *FrameworkPos = strstr(ContextName, ".framework");
+  if (FrameworkPos == 0 || 
+      (FrameworkPos[DotFrameworkLen] != '/' && 
+       FrameworkPos[DotFrameworkLen] != '\\'))
+    return 0;
+
+  SmallString<1024> FrameworkName(ContextName, FrameworkPos+DotFrameworkLen+1);
+
+  // Append Frameworks/HIToolbox.framework/
+  FrameworkName += "Frameworks/";
+  FrameworkName.append(Filename.begin(), Filename.begin()+SlashPos);
+  FrameworkName += ".framework/";
+
+  llvm::StringMapEntry<FrameworkCacheEntry> &CacheLookup =
+    FrameworkMap.GetOrCreateValue(Filename.substr(0, SlashPos));
+
+  // Some other location?
+  if (CacheLookup.getValue().Directory &&
+      CacheLookup.getKeyLength() == FrameworkName.size() &&
+      memcmp(CacheLookup.getKeyData(), &FrameworkName[0],
+             CacheLookup.getKeyLength()) != 0)
+    return 0;
+
+  // Cache subframework.
+  if (CacheLookup.getValue().Directory == 0) {
+    ++NumSubFrameworkLookups;
+
+    // If the framework dir doesn't exist, we fail.
+    const DirectoryEntry *Dir = FileMgr.getDirectory(FrameworkName.str());
+    if (Dir == 0) return 0;
+
+    // Otherwise, if it does, remember that this is the right direntry for this
+    // framework.
+    CacheLookup.getValue().Directory = Dir;
+  }
+
+  const FileEntry *FE = 0;
+
+  if (RelativePath != NULL) {
+    RelativePath->clear();
+    RelativePath->append(Filename.begin()+SlashPos+1, Filename.end());
+  }
+
+  // Check ".../Frameworks/HIToolbox.framework/Headers/HIToolbox.h"
+  SmallString<1024> HeadersFilename(FrameworkName);
+  HeadersFilename += "Headers/";
+  if (SearchPath != NULL) {
+    SearchPath->clear();
+    // Without trailing '/'.
+    SearchPath->append(HeadersFilename.begin(), HeadersFilename.end()-1);
+  }
+
+  HeadersFilename.append(Filename.begin()+SlashPos+1, Filename.end());
+  if (!(FE = FileMgr.getFile(HeadersFilename.str(), /*openFile=*/true))) {
+
+    // Check ".../Frameworks/HIToolbox.framework/PrivateHeaders/HIToolbox.h"
+    HeadersFilename = FrameworkName;
+    HeadersFilename += "PrivateHeaders/";
+    if (SearchPath != NULL) {
+      SearchPath->clear();
+      // Without trailing '/'.
+      SearchPath->append(HeadersFilename.begin(), HeadersFilename.end()-1);
+    }
+
+    HeadersFilename.append(Filename.begin()+SlashPos+1, Filename.end());
+    if (!(FE = FileMgr.getFile(HeadersFilename.str(), /*openFile=*/true)))
+      return 0;
+  }
+
+  // This file is a system header or C++ unfriendly if the old file is.
+  //
+  // Note that the temporary 'DirInfo' is required here, as either call to
+  // getFileInfo could resize the vector and we don't want to rely on order
+  // of evaluation.
+  unsigned DirInfo = getFileInfo(ContextFileEnt).DirInfo;
+  getFileInfo(FE).DirInfo = DirInfo;
+  return FE;
+}
+
+/// \brief Helper static function to normalize a path for injection into
+/// a synthetic header.
+/*static*/ std::string
+HeaderSearch::NormalizeDashIncludePath(StringRef File, FileManager &FileMgr) {
+  // Implicit include paths should be resolved relative to the current
+  // working directory first, and then use the regular header search
+  // mechanism. The proper way to handle this is to have the
+  // predefines buffer located at the current working directory, but
+  // it has no file entry. For now, workaround this by using an
+  // absolute path if we find the file here, and otherwise letting
+  // header search handle it.
+  SmallString<128> Path(File);
+  llvm::sys::fs::make_absolute(Path);
+  bool exists;
+  if (llvm::sys::fs::exists(Path.str(), exists) || !exists)
+    Path = File;
+  else if (exists)
+    FileMgr.getFile(File);
+
+  return Lexer::Stringify(Path.str());
+}
+
+//===----------------------------------------------------------------------===//
+// File Info Management.
+//===----------------------------------------------------------------------===//
+
+/// \brief Merge the header file info provided by \p OtherHFI into the current
+/// header file info (\p HFI)
+static void mergeHeaderFileInfo(HeaderFileInfo &HFI, 
+                                const HeaderFileInfo &OtherHFI) {
+  HFI.isImport |= OtherHFI.isImport;
+  HFI.isPragmaOnce |= OtherHFI.isPragmaOnce;
+  HFI.NumIncludes += OtherHFI.NumIncludes;
+  
+  if (!HFI.ControllingMacro && !HFI.ControllingMacroID) {
+    HFI.ControllingMacro = OtherHFI.ControllingMacro;
+    HFI.ControllingMacroID = OtherHFI.ControllingMacroID;
+  }
+  
+  if (OtherHFI.External) {
+    HFI.DirInfo = OtherHFI.DirInfo;
+    HFI.External = OtherHFI.External;
+    HFI.IndexHeaderMapHeader = OtherHFI.IndexHeaderMapHeader;
+  }
+
+  if (HFI.Framework.empty())
+    HFI.Framework = OtherHFI.Framework;
+  
+  HFI.Resolved = true;
+}
+                                
+/// getFileInfo - Return the HeaderFileInfo structure for the specified
+/// FileEntry.
+HeaderFileInfo &HeaderSearch::getFileInfo(const FileEntry *FE) {
+  if (FE->getUID() >= FileInfo.size())
+    FileInfo.resize(FE->getUID()+1);
+  
+  HeaderFileInfo &HFI = FileInfo[FE->getUID()];
+  if (ExternalSource && !HFI.Resolved)
+    mergeHeaderFileInfo(HFI, ExternalSource->GetHeaderFileInfo(FE));
+  return HFI;
+}
+
+bool HeaderSearch::isFileMultipleIncludeGuarded(const FileEntry *File) {
+  // Check if we've ever seen this file as a header.
+  if (File->getUID() >= FileInfo.size())
+    return false;
+
+  // Resolve header file info from the external source, if needed.
+  HeaderFileInfo &HFI = FileInfo[File->getUID()];
+  if (ExternalSource && !HFI.Resolved)
+    mergeHeaderFileInfo(HFI, ExternalSource->GetHeaderFileInfo(File));
+
+  return HFI.isPragmaOnce || HFI.ControllingMacro || HFI.ControllingMacroID;
+}
+
+void HeaderSearch::setHeaderFileInfoForUID(HeaderFileInfo HFI, unsigned UID) {
+  if (UID >= FileInfo.size())
+    FileInfo.resize(UID+1);
+  HFI.Resolved = true;
+  FileInfo[UID] = HFI;
+}
+
+/// ShouldEnterIncludeFile - Mark the specified file as a target of of a
+/// #include, #include_next, or #import directive.  Return false if #including
+/// the file will have no effect or true if we should include it.
+bool HeaderSearch::ShouldEnterIncludeFile(const FileEntry *File, bool isImport){
+  ++NumIncluded; // Count # of attempted #includes.
+
+  // Get information about this file.
+  HeaderFileInfo &FileInfo = getFileInfo(File);
+
+  // If this is a #import directive, check that we have not already imported
+  // this header.
+  if (isImport) {
+    // If this has already been imported, don't import it again.
+    FileInfo.isImport = true;
+
+    // Has this already been #import'ed or #include'd?
+    if (FileInfo.NumIncludes) return false;
+  } else {
+    // Otherwise, if this is a #include of a file that was previously #import'd
+    // or if this is the second #include of a #pragma once file, ignore it.
+    if (FileInfo.isImport)
+      return false;
+  }
+
+  // Next, check to see if the file is wrapped with #ifndef guards.  If so, and
+  // if the macro that guards it is defined, we know the #include has no effect.
+  if (const IdentifierInfo *ControllingMacro
+      = FileInfo.getControllingMacro(ExternalLookup))
+    if (ControllingMacro->hasMacroDefinition()) {
+      ++NumMultiIncludeFileOptzn;
+      return false;
+    }
+
+  // Increment the number of times this file has been included.
+  ++FileInfo.NumIncludes;
+
+  return true;
+}
+
+size_t HeaderSearch::getTotalMemory() const {
+  return SearchDirs.capacity()
+    + llvm::capacity_in_bytes(FileInfo)
+    + llvm::capacity_in_bytes(HeaderMaps)
+    + LookupFileCache.getAllocator().getTotalMemory()
+    + FrameworkMap.getAllocator().getTotalMemory();
+}
+
+StringRef HeaderSearch::getUniqueFrameworkName(StringRef Framework) {
+  return FrameworkNames.GetOrCreateValue(Framework).getKey();
+}
+
+bool HeaderSearch::hasModuleMap(StringRef FileName, 
+                                const DirectoryEntry *Root) {
+  llvm::SmallVector<const DirectoryEntry *, 2> FixUpDirectories;
+  
+  StringRef DirName = FileName;
+  do {
+    // Get the parent directory name.
+    DirName = llvm::sys::path::parent_path(DirName);
+    if (DirName.empty())
+      return false;
+    
+    // Determine whether this directory exists.
+    const DirectoryEntry *Dir = FileMgr.getDirectory(DirName);
+    if (!Dir)
+      return false;
+    
+    // Try to load the module map file in this directory.
+    switch (loadModuleMapFile(Dir)) {
+    case LMM_NewlyLoaded:
+    case LMM_AlreadyLoaded:
+      // Success. All of the directories we stepped through inherit this module
+      // map file.
+      for (unsigned I = 0, N = FixUpDirectories.size(); I != N; ++I)
+        DirectoryHasModuleMap[FixUpDirectories[I]] = true;
+      
+      return true;
+
+    case LMM_NoDirectory:
+    case LMM_InvalidModuleMap:
+      break;
+    }
+
+    // If we hit the top of our search, we're done.
+    if (Dir == Root)
+      return false;
+        
+    // Keep track of all of the directories we checked, so we can mark them as
+    // having module maps if we eventually do find a module map.
+    FixUpDirectories.push_back(Dir);
+  } while (true);
+}
+
+Module *HeaderSearch::findModuleForHeader(const FileEntry *File) {
+  if (Module *Mod = ModMap.findModuleForHeader(File))
+    return Mod;
+  
+  return 0;
+}
+
+bool HeaderSearch::loadModuleMapFile(const FileEntry *File) {
+  const DirectoryEntry *Dir = File->getDir();
+  
+  llvm::DenseMap<const DirectoryEntry *, bool>::iterator KnownDir
+    = DirectoryHasModuleMap.find(Dir);
+  if (KnownDir != DirectoryHasModuleMap.end())
+    return !KnownDir->second;
+  
+  bool Result = ModMap.parseModuleMapFile(File);
+  if (!Result && llvm::sys::path::filename(File->getName()) == "module.map") {
+    // If the file we loaded was a module.map, look for the corresponding
+    // module_private.map.
+    SmallString<128> PrivateFilename(Dir->getName());
+    llvm::sys::path::append(PrivateFilename, "module_private.map");
+    if (const FileEntry *PrivateFile = FileMgr.getFile(PrivateFilename))
+      Result = ModMap.parseModuleMapFile(PrivateFile);
+  }
+  
+  DirectoryHasModuleMap[Dir] = !Result;  
+  return Result;
+}
+
+Module *HeaderSearch::loadFrameworkModule(StringRef Name, 
+                                          const DirectoryEntry *Dir,
+                                          bool IsSystem) {
+  if (Module *Module = ModMap.findModule(Name))
+    return Module;
+  
+  // Try to load a module map file.
+  switch (loadModuleMapFile(Dir)) {
+  case LMM_InvalidModuleMap:
+    break;
+    
+  case LMM_AlreadyLoaded:
+  case LMM_NoDirectory:
+    return 0;
+    
+  case LMM_NewlyLoaded:
+    return ModMap.findModule(Name);
+  }
+
+  // The top-level framework directory, from which we'll infer a framework
+  // module.
+  const DirectoryEntry *TopFrameworkDir = Dir;
+  
+  // The path from the module we're actually looking for back to the top-level
+  // framework name.
+  llvm::SmallVector<StringRef, 2> SubmodulePath;
+  SubmodulePath.push_back(Name);
+  
+  // Walk the directory structure to find any enclosing frameworks.
+  StringRef DirName = Dir->getName();
+  do {
+    // Get the parent directory name.
+    DirName = llvm::sys::path::parent_path(DirName);
+    if (DirName.empty())
+      break;
+    
+    // Determine whether this directory exists.
+    Dir = FileMgr.getDirectory(DirName);
+    if (!Dir)
+      break;
+    
+    // If this is a framework directory, then we're a subframework of this
+    // framework.
+    if (llvm::sys::path::extension(DirName) == ".framework") {
+      SubmodulePath.push_back(llvm::sys::path::stem(DirName));
+      TopFrameworkDir = Dir;
+    }
+  } while (true);
+  
+  // Try to infer a module map from the top-level framework directory.
+  Module *Result = ModMap.inferFrameworkModule(SubmodulePath.back(), 
+                                               TopFrameworkDir,
+                                               IsSystem,
+                                               /*Parent=*/0);
+  
+  // Follow the submodule path to find the requested (sub)framework module
+  // within the top-level framework module.
+  SubmodulePath.pop_back();
+  while (!SubmodulePath.empty() && Result) {
+    Result = ModMap.lookupModuleQualified(SubmodulePath.back(), Result);
+    SubmodulePath.pop_back();
+  }
+  return Result;
+}
+
+
+HeaderSearch::LoadModuleMapResult 
+HeaderSearch::loadModuleMapFile(StringRef DirName) {
+  if (const DirectoryEntry *Dir = FileMgr.getDirectory(DirName))
+    return loadModuleMapFile(Dir);
+  
+  return LMM_NoDirectory;
+}
+
+HeaderSearch::LoadModuleMapResult 
+HeaderSearch::loadModuleMapFile(const DirectoryEntry *Dir) {
+  llvm::DenseMap<const DirectoryEntry *, bool>::iterator KnownDir
+    = DirectoryHasModuleMap.find(Dir);
+  if (KnownDir != DirectoryHasModuleMap.end())
+    return KnownDir->second? LMM_AlreadyLoaded : LMM_InvalidModuleMap;
+  
+  SmallString<128> ModuleMapFileName;
+  ModuleMapFileName += Dir->getName();
+  unsigned ModuleMapDirNameLen = ModuleMapFileName.size();
+  llvm::sys::path::append(ModuleMapFileName, "module.map");
+  if (const FileEntry *ModuleMapFile = FileMgr.getFile(ModuleMapFileName)) {
+    // We have found a module map file. Try to parse it.
+    if (ModMap.parseModuleMapFile(ModuleMapFile)) {
+      // No suitable module map.
+      DirectoryHasModuleMap[Dir] = false;
+      return LMM_InvalidModuleMap;
+    }
+
+    // This directory has a module map.
+    DirectoryHasModuleMap[Dir] = true;
+    
+    // Check whether there is a private module map that we need to load as well.
+    ModuleMapFileName.erase(ModuleMapFileName.begin() + ModuleMapDirNameLen,
+                            ModuleMapFileName.end());
+    llvm::sys::path::append(ModuleMapFileName, "module_private.map");
+    if (const FileEntry *PrivateModuleMapFile
+                                        = FileMgr.getFile(ModuleMapFileName)) {
+      if (ModMap.parseModuleMapFile(PrivateModuleMapFile)) {
+        // No suitable module map.
+        DirectoryHasModuleMap[Dir] = false;
+        return LMM_InvalidModuleMap;
+      }      
+    }
+    
+    return LMM_NewlyLoaded;
+  }
+  
+  // No suitable module map.
+  DirectoryHasModuleMap[Dir] = false;
+  return LMM_InvalidModuleMap;
+}
+
+void HeaderSearch::collectAllModules(llvm::SmallVectorImpl<Module *> &Modules) {
+  Modules.clear();
+  
+  // Load module maps for each of the header search directories.
+  for (unsigned Idx = 0, N = SearchDirs.size(); Idx != N; ++Idx) {
+    if (SearchDirs[Idx].isFramework()) {
+      llvm::error_code EC;
+      SmallString<128> DirNative;
+      llvm::sys::path::native(SearchDirs[Idx].getFrameworkDir()->getName(),
+                              DirNative);
+      
+      // Search each of the ".framework" directories to load them as modules.
+      bool IsSystem = SearchDirs[Idx].getDirCharacteristic() != SrcMgr::C_User;
+      for (llvm::sys::fs::directory_iterator Dir(DirNative.str(), EC), DirEnd;
+           Dir != DirEnd && !EC; Dir.increment(EC)) {
+        if (llvm::sys::path::extension(Dir->path()) != ".framework")
+          continue;
+        
+        const DirectoryEntry *FrameworkDir = FileMgr.getDirectory(Dir->path());
+        if (!FrameworkDir)
+          continue;
+        
+        // Load this framework module.
+        loadFrameworkModule(llvm::sys::path::stem(Dir->path()), FrameworkDir,
+                            IsSystem);
+      }
+      continue;
+    }
+    
+    // FIXME: Deal with header maps.
+    if (SearchDirs[Idx].isHeaderMap())
+      continue;
+    
+    // Try to load a module map file for the search directory.
+    loadModuleMapFile(SearchDirs[Idx].getDir());
+    
+    // Try to load module map files for immediate subdirectories of this search
+    // directory.
+    llvm::error_code EC;
+    SmallString<128> DirNative;
+    llvm::sys::path::native(SearchDirs[Idx].getDir()->getName(), DirNative);
+    for (llvm::sys::fs::directory_iterator Dir(DirNative.str(), EC), DirEnd;
+         Dir != DirEnd && !EC; Dir.increment(EC)) {
+      loadModuleMapFile(Dir->path());
+    }
+  }
+  
+  // Populate the list of modules.
+  for (ModuleMap::module_iterator M = ModMap.module_begin(), 
+                               MEnd = ModMap.module_end();
+       M != MEnd; ++M) {
+    Modules.push_back(M->getValue());
+  }
+}
+