diff --git a/lib/Basic/SourceManager.cpp b/lib/Basic/SourceManager.cpp
new file mode 100644
index 0000000..354bf7b
--- /dev/null
+++ b/lib/Basic/SourceManager.cpp
@@ -0,0 +1,1136 @@
+//===--- SourceManager.cpp - Track and cache source files -----------------===//
+//
+//                     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 SourceManager interface.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/SourceManagerInternals.h"
+#include "clang/Basic/FileManager.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/System/Path.h"
+#include <algorithm>
+using namespace clang;
+using namespace SrcMgr;
+using llvm::MemoryBuffer;
+
+//===----------------------------------------------------------------------===//
+// SourceManager Helper Classes
+//===----------------------------------------------------------------------===//
+
+ContentCache::~ContentCache() {
+  delete Buffer;
+}
+
+/// getSizeBytesMapped - Returns the number of bytes actually mapped for
+///  this ContentCache.  This can be 0 if the MemBuffer was not actually
+///  instantiated.
+unsigned ContentCache::getSizeBytesMapped() const {
+  return Buffer ? Buffer->getBufferSize() : 0;
+}
+
+/// getSize - Returns the size of the content encapsulated by this ContentCache.
+///  This can be the size of the source file or the size of an arbitrary
+///  scratch buffer.  If the ContentCache encapsulates a source file, that
+///  file is not lazily brought in from disk to satisfy this query.
+unsigned ContentCache::getSize() const {
+  return Buffer ? Buffer->getBufferSize() : Entry->getSize();
+}
+
+void ContentCache::replaceBuffer(const llvm::MemoryBuffer *B) {
+  assert(B != Buffer);
+  
+  delete Buffer;
+  Buffer = B;
+}
+
+const llvm::MemoryBuffer *ContentCache::getBuffer(std::string *ErrorStr) const {
+  // Lazily create the Buffer for ContentCaches that wrap files.
+  if (!Buffer && Entry) {
+    Buffer = MemoryBuffer::getFile(Entry->getName(), ErrorStr,Entry->getSize());
+
+    // If we were unable to open the file, then we are in an inconsistent
+    // situation where the content cache referenced a file which no longer
+    // exists. Most likely, we were using a stat cache with an invalid entry but
+    // the file could also have been removed during processing. Since we can't
+    // really deal with this situation, just create an empty buffer.
+    //
+    // FIXME: This is definitely not ideal, but our immediate clients can't
+    // currently handle returning a null entry here. Ideally we should detect
+    // that we are in an inconsistent situation and error out as quickly as
+    // possible.
+    if (!Buffer) {
+      const llvm::StringRef FillStr("<<<MISSING SOURCE FILE>>>\n");
+      Buffer = MemoryBuffer::getNewMemBuffer(Entry->getSize(), "<invalid>");
+      char *Ptr = const_cast<char*>(Buffer->getBufferStart());
+      for (unsigned i = 0, e = Entry->getSize(); i != e; ++i)
+        Ptr[i] = FillStr[i % FillStr.size()];
+    }
+  }
+  return Buffer;
+}
+
+unsigned LineTableInfo::getLineTableFilenameID(const char *Ptr, unsigned Len) {
+  // Look up the filename in the string table, returning the pre-existing value
+  // if it exists.
+  llvm::StringMapEntry<unsigned> &Entry =
+    FilenameIDs.GetOrCreateValue(Ptr, Ptr+Len, ~0U);
+  if (Entry.getValue() != ~0U)
+    return Entry.getValue();
+
+  // Otherwise, assign this the next available ID.
+  Entry.setValue(FilenamesByID.size());
+  FilenamesByID.push_back(&Entry);
+  return FilenamesByID.size()-1;
+}
+
+/// AddLineNote - Add a line note to the line table that indicates that there
+/// is a #line at the specified FID/Offset location which changes the presumed
+/// location to LineNo/FilenameID.
+void LineTableInfo::AddLineNote(unsigned FID, unsigned Offset,
+                                unsigned LineNo, int FilenameID) {
+  std::vector<LineEntry> &Entries = LineEntries[FID];
+
+  assert((Entries.empty() || Entries.back().FileOffset < Offset) &&
+         "Adding line entries out of order!");
+
+  SrcMgr::CharacteristicKind Kind = SrcMgr::C_User;
+  unsigned IncludeOffset = 0;
+
+  if (!Entries.empty()) {
+    // If this is a '#line 4' after '#line 42 "foo.h"', make sure to remember
+    // that we are still in "foo.h".
+    if (FilenameID == -1)
+      FilenameID = Entries.back().FilenameID;
+
+    // If we are after a line marker that switched us to system header mode, or
+    // that set #include information, preserve it.
+    Kind = Entries.back().FileKind;
+    IncludeOffset = Entries.back().IncludeOffset;
+  }
+
+  Entries.push_back(LineEntry::get(Offset, LineNo, FilenameID, Kind,
+                                   IncludeOffset));
+}
+
+/// AddLineNote This is the same as the previous version of AddLineNote, but is
+/// used for GNU line markers.  If EntryExit is 0, then this doesn't change the
+/// presumed #include stack.  If it is 1, this is a file entry, if it is 2 then
+/// this is a file exit.  FileKind specifies whether this is a system header or
+/// extern C system header.
+void LineTableInfo::AddLineNote(unsigned FID, unsigned Offset,
+                                unsigned LineNo, int FilenameID,
+                                unsigned EntryExit,
+                                SrcMgr::CharacteristicKind FileKind) {
+  assert(FilenameID != -1 && "Unspecified filename should use other accessor");
+
+  std::vector<LineEntry> &Entries = LineEntries[FID];
+
+  assert((Entries.empty() || Entries.back().FileOffset < Offset) &&
+         "Adding line entries out of order!");
+
+  unsigned IncludeOffset = 0;
+  if (EntryExit == 0) {  // No #include stack change.
+    IncludeOffset = Entries.empty() ? 0 : Entries.back().IncludeOffset;
+  } else if (EntryExit == 1) {
+    IncludeOffset = Offset-1;
+  } else if (EntryExit == 2) {
+    assert(!Entries.empty() && Entries.back().IncludeOffset &&
+       "PPDirectives should have caught case when popping empty include stack");
+
+    // Get the include loc of the last entries' include loc as our include loc.
+    IncludeOffset = 0;
+    if (const LineEntry *PrevEntry =
+          FindNearestLineEntry(FID, Entries.back().IncludeOffset))
+      IncludeOffset = PrevEntry->IncludeOffset;
+  }
+
+  Entries.push_back(LineEntry::get(Offset, LineNo, FilenameID, FileKind,
+                                   IncludeOffset));
+}
+
+
+/// FindNearestLineEntry - Find the line entry nearest to FID that is before
+/// it.  If there is no line entry before Offset in FID, return null.
+const LineEntry *LineTableInfo::FindNearestLineEntry(unsigned FID,
+                                                     unsigned Offset) {
+  const std::vector<LineEntry> &Entries = LineEntries[FID];
+  assert(!Entries.empty() && "No #line entries for this FID after all!");
+
+  // It is very common for the query to be after the last #line, check this
+  // first.
+  if (Entries.back().FileOffset <= Offset)
+    return &Entries.back();
+
+  // Do a binary search to find the maximal element that is still before Offset.
+  std::vector<LineEntry>::const_iterator I =
+    std::upper_bound(Entries.begin(), Entries.end(), Offset);
+  if (I == Entries.begin()) return 0;
+  return &*--I;
+}
+
+/// \brief Add a new line entry that has already been encoded into
+/// the internal representation of the line table.
+void LineTableInfo::AddEntry(unsigned FID,
+                             const std::vector<LineEntry> &Entries) {
+  LineEntries[FID] = Entries;
+}
+
+/// getLineTableFilenameID - Return the uniqued ID for the specified filename.
+///
+unsigned SourceManager::getLineTableFilenameID(const char *Ptr, unsigned Len) {
+  if (LineTable == 0)
+    LineTable = new LineTableInfo();
+  return LineTable->getLineTableFilenameID(Ptr, Len);
+}
+
+
+/// AddLineNote - Add a line note to the line table for the FileID and offset
+/// specified by Loc.  If FilenameID is -1, it is considered to be
+/// unspecified.
+void SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
+                                int FilenameID) {
+  std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
+
+  const SrcMgr::FileInfo &FileInfo = getSLocEntry(LocInfo.first).getFile();
+
+  // Remember that this file has #line directives now if it doesn't already.
+  const_cast<SrcMgr::FileInfo&>(FileInfo).setHasLineDirectives();
+
+  if (LineTable == 0)
+    LineTable = new LineTableInfo();
+  LineTable->AddLineNote(LocInfo.first.ID, LocInfo.second, LineNo, FilenameID);
+}
+
+/// AddLineNote - Add a GNU line marker to the line table.
+void SourceManager::AddLineNote(SourceLocation Loc, unsigned LineNo,
+                                int FilenameID, bool IsFileEntry,
+                                bool IsFileExit, bool IsSystemHeader,
+                                bool IsExternCHeader) {
+  // If there is no filename and no flags, this is treated just like a #line,
+  // which does not change the flags of the previous line marker.
+  if (FilenameID == -1) {
+    assert(!IsFileEntry && !IsFileExit && !IsSystemHeader && !IsExternCHeader &&
+           "Can't set flags without setting the filename!");
+    return AddLineNote(Loc, LineNo, FilenameID);
+  }
+
+  std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
+  const SrcMgr::FileInfo &FileInfo = getSLocEntry(LocInfo.first).getFile();
+
+  // Remember that this file has #line directives now if it doesn't already.
+  const_cast<SrcMgr::FileInfo&>(FileInfo).setHasLineDirectives();
+
+  if (LineTable == 0)
+    LineTable = new LineTableInfo();
+
+  SrcMgr::CharacteristicKind FileKind;
+  if (IsExternCHeader)
+    FileKind = SrcMgr::C_ExternCSystem;
+  else if (IsSystemHeader)
+    FileKind = SrcMgr::C_System;
+  else
+    FileKind = SrcMgr::C_User;
+
+  unsigned EntryExit = 0;
+  if (IsFileEntry)
+    EntryExit = 1;
+  else if (IsFileExit)
+    EntryExit = 2;
+
+  LineTable->AddLineNote(LocInfo.first.ID, LocInfo.second, LineNo, FilenameID,
+                         EntryExit, FileKind);
+}
+
+LineTableInfo &SourceManager::getLineTable() {
+  if (LineTable == 0)
+    LineTable = new LineTableInfo();
+  return *LineTable;
+}
+
+//===----------------------------------------------------------------------===//
+// Private 'Create' methods.
+//===----------------------------------------------------------------------===//
+
+SourceManager::~SourceManager() {
+  delete LineTable;
+
+  // Delete FileEntry objects corresponding to content caches.  Since the actual
+  // content cache objects are bump pointer allocated, we just have to run the
+  // dtors, but we call the deallocate method for completeness.
+  for (unsigned i = 0, e = MemBufferInfos.size(); i != e; ++i) {
+    MemBufferInfos[i]->~ContentCache();
+    ContentCacheAlloc.Deallocate(MemBufferInfos[i]);
+  }
+  for (llvm::DenseMap<const FileEntry*, SrcMgr::ContentCache*>::iterator
+       I = FileInfos.begin(), E = FileInfos.end(); I != E; ++I) {
+    I->second->~ContentCache();
+    ContentCacheAlloc.Deallocate(I->second);
+  }
+}
+
+void SourceManager::clearIDTables() {
+  MainFileID = FileID();
+  SLocEntryTable.clear();
+  LastLineNoFileIDQuery = FileID();
+  LastLineNoContentCache = 0;
+  LastFileIDLookup = FileID();
+
+  if (LineTable)
+    LineTable->clear();
+
+  // Use up FileID #0 as an invalid instantiation.
+  NextOffset = 0;
+  createInstantiationLoc(SourceLocation(),SourceLocation(),SourceLocation(), 1);
+}
+
+/// getOrCreateContentCache - Create or return a cached ContentCache for the
+/// specified file.
+const ContentCache *
+SourceManager::getOrCreateContentCache(const FileEntry *FileEnt) {
+  assert(FileEnt && "Didn't specify a file entry to use?");
+
+  // Do we already have information about this file?
+  ContentCache *&Entry = FileInfos[FileEnt];
+  if (Entry) return Entry;
+
+  // Nope, create a new Cache entry.  Make sure it is at least 8-byte aligned
+  // so that FileInfo can use the low 3 bits of the pointer for its own
+  // nefarious purposes.
+  unsigned EntryAlign = llvm::AlignOf<ContentCache>::Alignment;
+  EntryAlign = std::max(8U, EntryAlign);
+  Entry = ContentCacheAlloc.Allocate<ContentCache>(1, EntryAlign);
+  new (Entry) ContentCache(FileEnt);
+  return Entry;
+}
+
+
+/// createMemBufferContentCache - Create a new ContentCache for the specified
+///  memory buffer.  This does no caching.
+const ContentCache*
+SourceManager::createMemBufferContentCache(const MemoryBuffer *Buffer) {
+  // Add a new ContentCache to the MemBufferInfos list and return it.  Make sure
+  // it is at least 8-byte aligned so that FileInfo can use the low 3 bits of
+  // the pointer for its own nefarious purposes.
+  unsigned EntryAlign = llvm::AlignOf<ContentCache>::Alignment;
+  EntryAlign = std::max(8U, EntryAlign);
+  ContentCache *Entry = ContentCacheAlloc.Allocate<ContentCache>(1, EntryAlign);
+  new (Entry) ContentCache();
+  MemBufferInfos.push_back(Entry);
+  Entry->setBuffer(Buffer);
+  return Entry;
+}
+
+void SourceManager::PreallocateSLocEntries(ExternalSLocEntrySource *Source,
+                                           unsigned NumSLocEntries,
+                                           unsigned NextOffset) {
+  ExternalSLocEntries = Source;
+  this->NextOffset = NextOffset;
+  SLocEntryLoaded.resize(NumSLocEntries + 1);
+  SLocEntryLoaded[0] = true;
+  SLocEntryTable.resize(SLocEntryTable.size() + NumSLocEntries);
+}
+
+void SourceManager::ClearPreallocatedSLocEntries() {
+  unsigned I = 0;
+  for (unsigned N = SLocEntryLoaded.size(); I != N; ++I)
+    if (!SLocEntryLoaded[I])
+      break;
+
+  // We've already loaded all preallocated source location entries.
+  if (I == SLocEntryLoaded.size())
+    return;
+
+  // Remove everything from location I onward.
+  SLocEntryTable.resize(I);
+  SLocEntryLoaded.clear();
+  ExternalSLocEntries = 0;
+}
+
+
+//===----------------------------------------------------------------------===//
+// Methods to create new FileID's and instantiations.
+//===----------------------------------------------------------------------===//
+
+/// createFileID - Create a new fileID for the specified ContentCache and
+/// include position.  This works regardless of whether the ContentCache
+/// corresponds to a file or some other input source.
+FileID SourceManager::createFileID(const ContentCache *File,
+                                   SourceLocation IncludePos,
+                                   SrcMgr::CharacteristicKind FileCharacter,
+                                   unsigned PreallocatedID,
+                                   unsigned Offset) {
+  if (PreallocatedID) {
+    // If we're filling in a preallocated ID, just load in the file
+    // entry and return.
+    assert(PreallocatedID < SLocEntryLoaded.size() &&
+           "Preallocate ID out-of-range");
+    assert(!SLocEntryLoaded[PreallocatedID] &&
+           "Source location entry already loaded");
+    assert(Offset && "Preallocate source location cannot have zero offset");
+    SLocEntryTable[PreallocatedID]
+      = SLocEntry::get(Offset, FileInfo::get(IncludePos, File, FileCharacter));
+    SLocEntryLoaded[PreallocatedID] = true;
+    FileID FID = FileID::get(PreallocatedID);
+    return LastFileIDLookup = FID;
+  }
+
+  SLocEntryTable.push_back(SLocEntry::get(NextOffset,
+                                          FileInfo::get(IncludePos, File,
+                                                        FileCharacter)));
+  unsigned FileSize = File->getSize();
+  assert(NextOffset+FileSize+1 > NextOffset && "Ran out of source locations!");
+  NextOffset += FileSize+1;
+
+  // Set LastFileIDLookup to the newly created file.  The next getFileID call is
+  // almost guaranteed to be from that file.
+  FileID FID = FileID::get(SLocEntryTable.size()-1);
+  return LastFileIDLookup = FID;
+}
+
+/// createInstantiationLoc - Return a new SourceLocation that encodes the fact
+/// that a token from SpellingLoc should actually be referenced from
+/// InstantiationLoc.
+SourceLocation SourceManager::createInstantiationLoc(SourceLocation SpellingLoc,
+                                                     SourceLocation ILocStart,
+                                                     SourceLocation ILocEnd,
+                                                     unsigned TokLength,
+                                                     unsigned PreallocatedID,
+                                                     unsigned Offset) {
+  InstantiationInfo II = InstantiationInfo::get(ILocStart,ILocEnd, SpellingLoc);
+  if (PreallocatedID) {
+    // If we're filling in a preallocated ID, just load in the
+    // instantiation entry and return.
+    assert(PreallocatedID < SLocEntryLoaded.size() &&
+           "Preallocate ID out-of-range");
+    assert(!SLocEntryLoaded[PreallocatedID] &&
+           "Source location entry already loaded");
+    assert(Offset && "Preallocate source location cannot have zero offset");
+    SLocEntryTable[PreallocatedID] = SLocEntry::get(Offset, II);
+    SLocEntryLoaded[PreallocatedID] = true;
+    return SourceLocation::getMacroLoc(Offset);
+  }
+  SLocEntryTable.push_back(SLocEntry::get(NextOffset, II));
+  assert(NextOffset+TokLength+1 > NextOffset && "Ran out of source locations!");
+  NextOffset += TokLength+1;
+  return SourceLocation::getMacroLoc(NextOffset-(TokLength+1));
+}
+
+const llvm::MemoryBuffer *
+SourceManager::getMemoryBufferForFile(const FileEntry *File) {
+  const SrcMgr::ContentCache *IR = getOrCreateContentCache(File);
+  if (IR == 0)
+    return 0;
+
+  return IR->getBuffer();
+}
+
+bool SourceManager::overrideFileContents(const FileEntry *SourceFile,
+                                         const llvm::MemoryBuffer *Buffer) {
+  const SrcMgr::ContentCache *IR = getOrCreateContentCache(SourceFile);
+  if (IR == 0)
+    return true;
+
+  const_cast<SrcMgr::ContentCache *>(IR)->replaceBuffer(Buffer);
+  return false;
+}
+
+/// getBufferData - Return a pointer to the start and end of the source buffer
+/// data for the specified FileID.
+std::pair<const char*, const char*>
+SourceManager::getBufferData(FileID FID) const {
+  const llvm::MemoryBuffer *Buf = getBuffer(FID);
+  return std::make_pair(Buf->getBufferStart(), Buf->getBufferEnd());
+}
+
+
+//===----------------------------------------------------------------------===//
+// SourceLocation manipulation methods.
+//===----------------------------------------------------------------------===//
+
+/// getFileIDSlow - Return the FileID for a SourceLocation.  This is a very hot
+/// method that is used for all SourceManager queries that start with a
+/// SourceLocation object.  It is responsible for finding the entry in
+/// SLocEntryTable which contains the specified location.
+///
+FileID SourceManager::getFileIDSlow(unsigned SLocOffset) const {
+  assert(SLocOffset && "Invalid FileID");
+
+  // After the first and second level caches, I see two common sorts of
+  // behavior: 1) a lot of searched FileID's are "near" the cached file location
+  // or are "near" the cached instantiation location.  2) others are just
+  // completely random and may be a very long way away.
+  //
+  // To handle this, we do a linear search for up to 8 steps to catch #1 quickly
+  // then we fall back to a less cache efficient, but more scalable, binary
+  // search to find the location.
+
+  // See if this is near the file point - worst case we start scanning from the
+  // most newly created FileID.
+  std::vector<SrcMgr::SLocEntry>::const_iterator I;
+
+  if (SLocEntryTable[LastFileIDLookup.ID].getOffset() < SLocOffset) {
+    // Neither loc prunes our search.
+    I = SLocEntryTable.end();
+  } else {
+    // Perhaps it is near the file point.
+    I = SLocEntryTable.begin()+LastFileIDLookup.ID;
+  }
+
+  // Find the FileID that contains this.  "I" is an iterator that points to a
+  // FileID whose offset is known to be larger than SLocOffset.
+  unsigned NumProbes = 0;
+  while (1) {
+    --I;
+    if (ExternalSLocEntries)
+      getSLocEntry(FileID::get(I - SLocEntryTable.begin()));
+    if (I->getOffset() <= SLocOffset) {
+#if 0
+      printf("lin %d -> %d [%s] %d %d\n", SLocOffset,
+             I-SLocEntryTable.begin(),
+             I->isInstantiation() ? "inst" : "file",
+             LastFileIDLookup.ID,  int(SLocEntryTable.end()-I));
+#endif
+      FileID Res = FileID::get(I-SLocEntryTable.begin());
+
+      // If this isn't an instantiation, remember it.  We have good locality
+      // across FileID lookups.
+      if (!I->isInstantiation())
+        LastFileIDLookup = Res;
+      NumLinearScans += NumProbes+1;
+      return Res;
+    }
+    if (++NumProbes == 8)
+      break;
+  }
+
+  // Convert "I" back into an index.  We know that it is an entry whose index is
+  // larger than the offset we are looking for.
+  unsigned GreaterIndex = I-SLocEntryTable.begin();
+  // LessIndex - This is the lower bound of the range that we're searching.
+  // We know that the offset corresponding to the FileID is is less than
+  // SLocOffset.
+  unsigned LessIndex = 0;
+  NumProbes = 0;
+  while (1) {
+    unsigned MiddleIndex = (GreaterIndex-LessIndex)/2+LessIndex;
+    unsigned MidOffset = getSLocEntry(FileID::get(MiddleIndex)).getOffset();
+
+    ++NumProbes;
+
+    // If the offset of the midpoint is too large, chop the high side of the
+    // range to the midpoint.
+    if (MidOffset > SLocOffset) {
+      GreaterIndex = MiddleIndex;
+      continue;
+    }
+
+    // If the middle index contains the value, succeed and return.
+    if (isOffsetInFileID(FileID::get(MiddleIndex), SLocOffset)) {
+#if 0
+      printf("bin %d -> %d [%s] %d %d\n", SLocOffset,
+             I-SLocEntryTable.begin(),
+             I->isInstantiation() ? "inst" : "file",
+             LastFileIDLookup.ID, int(SLocEntryTable.end()-I));
+#endif
+      FileID Res = FileID::get(MiddleIndex);
+
+      // If this isn't an instantiation, remember it.  We have good locality
+      // across FileID lookups.
+      if (!I->isInstantiation())
+        LastFileIDLookup = Res;
+      NumBinaryProbes += NumProbes;
+      return Res;
+    }
+
+    // Otherwise, move the low-side up to the middle index.
+    LessIndex = MiddleIndex;
+  }
+}
+
+SourceLocation SourceManager::
+getInstantiationLocSlowCase(SourceLocation Loc) const {
+  do {
+    std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(Loc);
+    Loc = getSLocEntry(LocInfo.first).getInstantiation()
+                   .getInstantiationLocStart();
+    Loc = Loc.getFileLocWithOffset(LocInfo.second);
+  } while (!Loc.isFileID());
+
+  return Loc;
+}
+
+SourceLocation SourceManager::getSpellingLocSlowCase(SourceLocation Loc) const {
+  do {
+    std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(Loc);
+    Loc = getSLocEntry(LocInfo.first).getInstantiation().getSpellingLoc();
+    Loc = Loc.getFileLocWithOffset(LocInfo.second);
+  } while (!Loc.isFileID());
+  return Loc;
+}
+
+
+std::pair<FileID, unsigned>
+SourceManager::getDecomposedInstantiationLocSlowCase(const SrcMgr::SLocEntry *E,
+                                                     unsigned Offset) const {
+  // If this is an instantiation record, walk through all the instantiation
+  // points.
+  FileID FID;
+  SourceLocation Loc;
+  do {
+    Loc = E->getInstantiation().getInstantiationLocStart();
+
+    FID = getFileID(Loc);
+    E = &getSLocEntry(FID);
+    Offset += Loc.getOffset()-E->getOffset();
+  } while (!Loc.isFileID());
+
+  return std::make_pair(FID, Offset);
+}
+
+std::pair<FileID, unsigned>
+SourceManager::getDecomposedSpellingLocSlowCase(const SrcMgr::SLocEntry *E,
+                                                unsigned Offset) const {
+  // If this is an instantiation record, walk through all the instantiation
+  // points.
+  FileID FID;
+  SourceLocation Loc;
+  do {
+    Loc = E->getInstantiation().getSpellingLoc();
+
+    FID = getFileID(Loc);
+    E = &getSLocEntry(FID);
+    Offset += Loc.getOffset()-E->getOffset();
+  } while (!Loc.isFileID());
+
+  return std::make_pair(FID, Offset);
+}
+
+/// getImmediateSpellingLoc - Given a SourceLocation object, return the
+/// spelling location referenced by the ID.  This is the first level down
+/// towards the place where the characters that make up the lexed token can be
+/// found.  This should not generally be used by clients.
+SourceLocation SourceManager::getImmediateSpellingLoc(SourceLocation Loc) const{
+  if (Loc.isFileID()) return Loc;
+  std::pair<FileID, unsigned> LocInfo = getDecomposedLoc(Loc);
+  Loc = getSLocEntry(LocInfo.first).getInstantiation().getSpellingLoc();
+  return Loc.getFileLocWithOffset(LocInfo.second);
+}
+
+
+/// getImmediateInstantiationRange - Loc is required to be an instantiation
+/// location.  Return the start/end of the instantiation information.
+std::pair<SourceLocation,SourceLocation>
+SourceManager::getImmediateInstantiationRange(SourceLocation Loc) const {
+  assert(Loc.isMacroID() && "Not an instantiation loc!");
+  const InstantiationInfo &II = getSLocEntry(getFileID(Loc)).getInstantiation();
+  return II.getInstantiationLocRange();
+}
+
+/// getInstantiationRange - Given a SourceLocation object, return the
+/// range of tokens covered by the instantiation in the ultimate file.
+std::pair<SourceLocation,SourceLocation>
+SourceManager::getInstantiationRange(SourceLocation Loc) const {
+  if (Loc.isFileID()) return std::make_pair(Loc, Loc);
+
+  std::pair<SourceLocation,SourceLocation> Res =
+    getImmediateInstantiationRange(Loc);
+
+  // Fully resolve the start and end locations to their ultimate instantiation
+  // points.
+  while (!Res.first.isFileID())
+    Res.first = getImmediateInstantiationRange(Res.first).first;
+  while (!Res.second.isFileID())
+    Res.second = getImmediateInstantiationRange(Res.second).second;
+  return Res;
+}
+
+
+
+//===----------------------------------------------------------------------===//
+// Queries about the code at a SourceLocation.
+//===----------------------------------------------------------------------===//
+
+/// getCharacterData - Return a pointer to the start of the specified location
+/// in the appropriate MemoryBuffer.
+const char *SourceManager::getCharacterData(SourceLocation SL) const {
+  // Note that this is a hot function in the getSpelling() path, which is
+  // heavily used by -E mode.
+  std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(SL);
+
+  // Note that calling 'getBuffer()' may lazily page in a source file.
+  return getSLocEntry(LocInfo.first).getFile().getContentCache()
+              ->getBuffer()->getBufferStart() + LocInfo.second;
+}
+
+
+/// getColumnNumber - Return the column # for the specified file position.
+/// this is significantly cheaper to compute than the line number.
+unsigned SourceManager::getColumnNumber(FileID FID, unsigned FilePos) const {
+  const char *Buf = getBuffer(FID)->getBufferStart();
+
+  unsigned LineStart = FilePos;
+  while (LineStart && Buf[LineStart-1] != '\n' && Buf[LineStart-1] != '\r')
+    --LineStart;
+  return FilePos-LineStart+1;
+}
+
+unsigned SourceManager::getSpellingColumnNumber(SourceLocation Loc) const {
+  if (Loc.isInvalid()) return 0;
+  std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(Loc);
+  return getColumnNumber(LocInfo.first, LocInfo.second);
+}
+
+unsigned SourceManager::getInstantiationColumnNumber(SourceLocation Loc) const {
+  if (Loc.isInvalid()) return 0;
+  std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
+  return getColumnNumber(LocInfo.first, LocInfo.second);
+}
+
+
+
+static DISABLE_INLINE void ComputeLineNumbers(ContentCache* FI,
+                                              llvm::BumpPtrAllocator &Alloc);
+static void ComputeLineNumbers(ContentCache* FI, llvm::BumpPtrAllocator &Alloc){
+  // Note that calling 'getBuffer()' may lazily page in the file.
+  const MemoryBuffer *Buffer = FI->getBuffer();
+
+  // Find the file offsets of all of the *physical* source lines.  This does
+  // not look at trigraphs, escaped newlines, or anything else tricky.
+  std::vector<unsigned> LineOffsets;
+
+  // Line #1 starts at char 0.
+  LineOffsets.push_back(0);
+
+  const unsigned char *Buf = (const unsigned char *)Buffer->getBufferStart();
+  const unsigned char *End = (const unsigned char *)Buffer->getBufferEnd();
+  unsigned Offs = 0;
+  while (1) {
+    // Skip over the contents of the line.
+    // TODO: Vectorize this?  This is very performance sensitive for programs
+    // with lots of diagnostics and in -E mode.
+    const unsigned char *NextBuf = (const unsigned char *)Buf;
+    while (*NextBuf != '\n' && *NextBuf != '\r' && *NextBuf != '\0')
+      ++NextBuf;
+    Offs += NextBuf-Buf;
+    Buf = NextBuf;
+
+    if (Buf[0] == '\n' || Buf[0] == '\r') {
+      // If this is \n\r or \r\n, skip both characters.
+      if ((Buf[1] == '\n' || Buf[1] == '\r') && Buf[0] != Buf[1])
+        ++Offs, ++Buf;
+      ++Offs, ++Buf;
+      LineOffsets.push_back(Offs);
+    } else {
+      // Otherwise, this is a null.  If end of file, exit.
+      if (Buf == End) break;
+      // Otherwise, skip the null.
+      ++Offs, ++Buf;
+    }
+  }
+
+  // Copy the offsets into the FileInfo structure.
+  FI->NumLines = LineOffsets.size();
+  FI->SourceLineCache = Alloc.Allocate<unsigned>(LineOffsets.size());
+  std::copy(LineOffsets.begin(), LineOffsets.end(), FI->SourceLineCache);
+}
+
+/// getLineNumber - Given a SourceLocation, return the spelling line number
+/// for the position indicated.  This requires building and caching a table of
+/// line offsets for the MemoryBuffer, so this is not cheap: use only when
+/// about to emit a diagnostic.
+unsigned SourceManager::getLineNumber(FileID FID, unsigned FilePos) const {
+  ContentCache *Content;
+  if (LastLineNoFileIDQuery == FID)
+    Content = LastLineNoContentCache;
+  else
+    Content = const_cast<ContentCache*>(getSLocEntry(FID)
+                                        .getFile().getContentCache());
+
+  // If this is the first use of line information for this buffer, compute the
+  /// SourceLineCache for it on demand.
+  if (Content->SourceLineCache == 0)
+    ComputeLineNumbers(Content, ContentCacheAlloc);
+
+  // Okay, we know we have a line number table.  Do a binary search to find the
+  // line number that this character position lands on.
+  unsigned *SourceLineCache = Content->SourceLineCache;
+  unsigned *SourceLineCacheStart = SourceLineCache;
+  unsigned *SourceLineCacheEnd = SourceLineCache + Content->NumLines;
+
+  unsigned QueriedFilePos = FilePos+1;
+
+  // FIXME: I would like to be convinced that this code is worth being as
+  // complicated as it is, binary search isn't that slow.
+  //
+  // If it is worth being optimized, then in my opinion it could be more
+  // performant, simpler, and more obviously correct by just "galloping" outward
+  // from the queried file position. In fact, this could be incorporated into a
+  // generic algorithm such as lower_bound_with_hint.
+  //
+  // If someone gives me a test case where this matters, and I will do it! - DWD
+
+  // If the previous query was to the same file, we know both the file pos from
+  // that query and the line number returned.  This allows us to narrow the
+  // search space from the entire file to something near the match.
+  if (LastLineNoFileIDQuery == FID) {
+    if (QueriedFilePos >= LastLineNoFilePos) {
+      // FIXME: Potential overflow?
+      SourceLineCache = SourceLineCache+LastLineNoResult-1;
+
+      // The query is likely to be nearby the previous one.  Here we check to
+      // see if it is within 5, 10 or 20 lines.  It can be far away in cases
+      // where big comment blocks and vertical whitespace eat up lines but
+      // contribute no tokens.
+      if (SourceLineCache+5 < SourceLineCacheEnd) {
+        if (SourceLineCache[5] > QueriedFilePos)
+          SourceLineCacheEnd = SourceLineCache+5;
+        else if (SourceLineCache+10 < SourceLineCacheEnd) {
+          if (SourceLineCache[10] > QueriedFilePos)
+            SourceLineCacheEnd = SourceLineCache+10;
+          else if (SourceLineCache+20 < SourceLineCacheEnd) {
+            if (SourceLineCache[20] > QueriedFilePos)
+              SourceLineCacheEnd = SourceLineCache+20;
+          }
+        }
+      }
+    } else {
+      if (LastLineNoResult < Content->NumLines)
+        SourceLineCacheEnd = SourceLineCache+LastLineNoResult+1;
+    }
+  }
+
+  // If the spread is large, do a "radix" test as our initial guess, based on
+  // the assumption that lines average to approximately the same length.
+  // NOTE: This is currently disabled, as it does not appear to be profitable in
+  // initial measurements.
+  if (0 && SourceLineCacheEnd-SourceLineCache > 20) {
+    unsigned FileLen = Content->SourceLineCache[Content->NumLines-1];
+
+    // Take a stab at guessing where it is.
+    unsigned ApproxPos = Content->NumLines*QueriedFilePos / FileLen;
+
+    // Check for -10 and +10 lines.
+    unsigned LowerBound = std::max(int(ApproxPos-10), 0);
+    unsigned UpperBound = std::min(ApproxPos+10, FileLen);
+
+    // If the computed lower bound is less than the query location, move it in.
+    if (SourceLineCache < SourceLineCacheStart+LowerBound &&
+        SourceLineCacheStart[LowerBound] < QueriedFilePos)
+      SourceLineCache = SourceLineCacheStart+LowerBound;
+
+    // If the computed upper bound is greater than the query location, move it.
+    if (SourceLineCacheEnd > SourceLineCacheStart+UpperBound &&
+        SourceLineCacheStart[UpperBound] >= QueriedFilePos)
+      SourceLineCacheEnd = SourceLineCacheStart+UpperBound;
+  }
+
+  unsigned *Pos
+    = std::lower_bound(SourceLineCache, SourceLineCacheEnd, QueriedFilePos);
+  unsigned LineNo = Pos-SourceLineCacheStart;
+
+  LastLineNoFileIDQuery = FID;
+  LastLineNoContentCache = Content;
+  LastLineNoFilePos = QueriedFilePos;
+  LastLineNoResult = LineNo;
+  return LineNo;
+}
+
+unsigned SourceManager::getInstantiationLineNumber(SourceLocation Loc) const {
+  if (Loc.isInvalid()) return 0;
+  std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
+  return getLineNumber(LocInfo.first, LocInfo.second);
+}
+unsigned SourceManager::getSpellingLineNumber(SourceLocation Loc) const {
+  if (Loc.isInvalid()) return 0;
+  std::pair<FileID, unsigned> LocInfo = getDecomposedSpellingLoc(Loc);
+  return getLineNumber(LocInfo.first, LocInfo.second);
+}
+
+/// getFileCharacteristic - return the file characteristic of the specified
+/// source location, indicating whether this is a normal file, a system
+/// header, or an "implicit extern C" system header.
+///
+/// This state can be modified with flags on GNU linemarker directives like:
+///   # 4 "foo.h" 3
+/// which changes all source locations in the current file after that to be
+/// considered to be from a system header.
+SrcMgr::CharacteristicKind
+SourceManager::getFileCharacteristic(SourceLocation Loc) const {
+  assert(!Loc.isInvalid() && "Can't get file characteristic of invalid loc!");
+  std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
+  const SrcMgr::FileInfo &FI = getSLocEntry(LocInfo.first).getFile();
+
+  // If there are no #line directives in this file, just return the whole-file
+  // state.
+  if (!FI.hasLineDirectives())
+    return FI.getFileCharacteristic();
+
+  assert(LineTable && "Can't have linetable entries without a LineTable!");
+  // See if there is a #line directive before the location.
+  const LineEntry *Entry =
+    LineTable->FindNearestLineEntry(LocInfo.first.ID, LocInfo.second);
+
+  // If this is before the first line marker, use the file characteristic.
+  if (!Entry)
+    return FI.getFileCharacteristic();
+
+  return Entry->FileKind;
+}
+
+/// Return the filename or buffer identifier of the buffer the location is in.
+/// Note that this name does not respect #line directives.  Use getPresumedLoc
+/// for normal clients.
+const char *SourceManager::getBufferName(SourceLocation Loc) const {
+  if (Loc.isInvalid()) return "<invalid loc>";
+
+  return getBuffer(getFileID(Loc))->getBufferIdentifier();
+}
+
+
+/// getPresumedLoc - This method returns the "presumed" location of a
+/// SourceLocation specifies.  A "presumed location" can be modified by #line
+/// or GNU line marker directives.  This provides a view on the data that a
+/// user should see in diagnostics, for example.
+///
+/// Note that a presumed location is always given as the instantiation point
+/// of an instantiation location, not at the spelling location.
+PresumedLoc SourceManager::getPresumedLoc(SourceLocation Loc) const {
+  if (Loc.isInvalid()) return PresumedLoc();
+
+  // Presumed locations are always for instantiation points.
+  std::pair<FileID, unsigned> LocInfo = getDecomposedInstantiationLoc(Loc);
+
+  const SrcMgr::FileInfo &FI = getSLocEntry(LocInfo.first).getFile();
+  const SrcMgr::ContentCache *C = FI.getContentCache();
+
+  // To get the source name, first consult the FileEntry (if one exists)
+  // before the MemBuffer as this will avoid unnecessarily paging in the
+  // MemBuffer.
+  const char *Filename =
+    C->Entry ? C->Entry->getName() : C->getBuffer()->getBufferIdentifier();
+  unsigned LineNo = getLineNumber(LocInfo.first, LocInfo.second);
+  unsigned ColNo  = getColumnNumber(LocInfo.first, LocInfo.second);
+  SourceLocation IncludeLoc = FI.getIncludeLoc();
+
+  // If we have #line directives in this file, update and overwrite the physical
+  // location info if appropriate.
+  if (FI.hasLineDirectives()) {
+    assert(LineTable && "Can't have linetable entries without a LineTable!");
+    // See if there is a #line directive before this.  If so, get it.
+    if (const LineEntry *Entry =
+          LineTable->FindNearestLineEntry(LocInfo.first.ID, LocInfo.second)) {
+      // If the LineEntry indicates a filename, use it.
+      if (Entry->FilenameID != -1)
+        Filename = LineTable->getFilename(Entry->FilenameID);
+
+      // Use the line number specified by the LineEntry.  This line number may
+      // be multiple lines down from the line entry.  Add the difference in
+      // physical line numbers from the query point and the line marker to the
+      // total.
+      unsigned MarkerLineNo = getLineNumber(LocInfo.first, Entry->FileOffset);
+      LineNo = Entry->LineNo + (LineNo-MarkerLineNo-1);
+
+      // Note that column numbers are not molested by line markers.
+
+      // Handle virtual #include manipulation.
+      if (Entry->IncludeOffset) {
+        IncludeLoc = getLocForStartOfFile(LocInfo.first);
+        IncludeLoc = IncludeLoc.getFileLocWithOffset(Entry->IncludeOffset);
+      }
+    }
+  }
+
+  return PresumedLoc(Filename, LineNo, ColNo, IncludeLoc);
+}
+
+//===----------------------------------------------------------------------===//
+// Other miscellaneous methods.
+//===----------------------------------------------------------------------===//
+
+/// \brief Get the source location for the given file:line:col triplet.
+///
+/// If the source file is included multiple times, the source location will
+/// be based upon the first inclusion.
+SourceLocation SourceManager::getLocation(const FileEntry *SourceFile,
+                                          unsigned Line, unsigned Col) const {
+  assert(SourceFile && "Null source file!");
+  assert(Line && Col && "Line and column should start from 1!");
+
+  fileinfo_iterator FI = FileInfos.find(SourceFile);
+  if (FI == FileInfos.end())
+    return SourceLocation();
+  ContentCache *Content = FI->second;
+
+  // If this is the first use of line information for this buffer, compute the
+  /// SourceLineCache for it on demand.
+  if (Content->SourceLineCache == 0)
+    ComputeLineNumbers(Content, ContentCacheAlloc);
+
+  if (Line > Content->NumLines)
+    return SourceLocation();
+
+  unsigned FilePos = Content->SourceLineCache[Line - 1];
+  const char *Buf = Content->getBuffer()->getBufferStart() + FilePos;
+  unsigned BufLength = Content->getBuffer()->getBufferEnd() - Buf;
+  unsigned i = 0;
+
+  // Check that the given column is valid.
+  while (i < BufLength-1 && i < Col-1 && Buf[i] != '\n' && Buf[i] != '\r')
+    ++i;
+  if (i < Col-1)
+    return SourceLocation();
+
+  // Find the first file ID that corresponds to the given file.
+  FileID FirstFID;
+
+  // First, check the main file ID, since it is common to look for a
+  // location in the main file.
+  if (!MainFileID.isInvalid()) {
+    const SLocEntry &MainSLoc = getSLocEntry(MainFileID);
+    if (MainSLoc.isFile() && MainSLoc.getFile().getContentCache() == Content)
+      FirstFID = MainFileID;
+  }
+
+  if (FirstFID.isInvalid()) {
+    // The location we're looking for isn't in the main file; look
+    // through all of the source locations.
+    for (unsigned I = 0, N = sloc_entry_size(); I != N; ++I) {
+      const SLocEntry &SLoc = getSLocEntry(I);
+      if (SLoc.isFile() && SLoc.getFile().getContentCache() == Content) {
+        FirstFID = FileID::get(I);
+        break;
+      }
+    }
+  }
+    
+  if (FirstFID.isInvalid())
+    return SourceLocation();
+
+  return getLocForStartOfFile(FirstFID).getFileLocWithOffset(FilePos + Col - 1);
+}
+
+/// \brief Determines the order of 2 source locations in the translation unit.
+///
+/// \returns true if LHS source location comes before RHS, false otherwise.
+bool SourceManager::isBeforeInTranslationUnit(SourceLocation LHS,
+                                              SourceLocation RHS) const {
+  assert(LHS.isValid() && RHS.isValid() && "Passed invalid source location!");
+  if (LHS == RHS)
+    return false;
+
+  std::pair<FileID, unsigned> LOffs = getDecomposedLoc(LHS);
+  std::pair<FileID, unsigned> ROffs = getDecomposedLoc(RHS);
+
+  // If the source locations are in the same file, just compare offsets.
+  if (LOffs.first == ROffs.first)
+    return LOffs.second < ROffs.second;
+
+  // If we are comparing a source location with multiple locations in the same
+  // file, we get a big win by caching the result.
+
+  if (LastLFIDForBeforeTUCheck == LOffs.first &&
+      LastRFIDForBeforeTUCheck == ROffs.first)
+    return LastResForBeforeTUCheck;
+
+  LastLFIDForBeforeTUCheck = LOffs.first;
+  LastRFIDForBeforeTUCheck = ROffs.first;
+
+  // "Traverse" the include/instantiation stacks of both locations and try to
+  // find a common "ancestor".
+  //
+  // First we traverse the stack of the right location and check each level
+  // against the level of the left location, while collecting all levels in a
+  // "stack map".
+
+  std::map<FileID, unsigned> ROffsMap;
+  ROffsMap[ROffs.first] = ROffs.second;
+
+  while (1) {
+    SourceLocation UpperLoc;
+    const SrcMgr::SLocEntry &Entry = getSLocEntry(ROffs.first);
+    if (Entry.isInstantiation())
+      UpperLoc = Entry.getInstantiation().getInstantiationLocStart();
+    else
+      UpperLoc = Entry.getFile().getIncludeLoc();
+
+    if (UpperLoc.isInvalid())
+      break; // We reached the top.
+
+    ROffs = getDecomposedLoc(UpperLoc);
+
+    if (LOffs.first == ROffs.first)
+      return LastResForBeforeTUCheck = LOffs.second < ROffs.second;
+
+    ROffsMap[ROffs.first] = ROffs.second;
+  }
+
+  // We didn't find a common ancestor. Now traverse the stack of the left
+  // location, checking against the stack map of the right location.
+
+  while (1) {
+    SourceLocation UpperLoc;
+    const SrcMgr::SLocEntry &Entry = getSLocEntry(LOffs.first);
+    if (Entry.isInstantiation())
+      UpperLoc = Entry.getInstantiation().getInstantiationLocStart();
+    else
+      UpperLoc = Entry.getFile().getIncludeLoc();
+
+    if (UpperLoc.isInvalid())
+      break; // We reached the top.
+
+    LOffs = getDecomposedLoc(UpperLoc);
+
+    std::map<FileID, unsigned>::iterator I = ROffsMap.find(LOffs.first);
+    if (I != ROffsMap.end())
+      return LastResForBeforeTUCheck = LOffs.second < I->second;
+  }
+
+  // There is no common ancestor, most probably because one location is in the
+  // predefines buffer.
+  //
+  // FIXME: We should rearrange the external interface so this simply never
+  // happens; it can't conceptually happen. Also see PR5662.
+
+  // If exactly one location is a memory buffer, assume it preceeds the other.
+  bool LIsMB = !getSLocEntry(LOffs.first).getFile().getContentCache()->Entry;
+  bool RIsMB = !getSLocEntry(ROffs.first).getFile().getContentCache()->Entry;
+  if (LIsMB != RIsMB)
+    return LastResForBeforeTUCheck = LIsMB;
+
+  // Otherwise, just assume FileIDs were created in order.
+  return LastResForBeforeTUCheck = (LOffs.first < ROffs.first);
+}
+
+/// PrintStats - Print statistics to stderr.
+///
+void SourceManager::PrintStats() const {
+  llvm::errs() << "\n*** Source Manager Stats:\n";
+  llvm::errs() << FileInfos.size() << " files mapped, " << MemBufferInfos.size()
+               << " mem buffers mapped.\n";
+  llvm::errs() << SLocEntryTable.size() << " SLocEntry's allocated, "
+               << NextOffset << "B of Sloc address space used.\n";
+
+  unsigned NumLineNumsComputed = 0;
+  unsigned NumFileBytesMapped = 0;
+  for (fileinfo_iterator I = fileinfo_begin(), E = fileinfo_end(); I != E; ++I){
+    NumLineNumsComputed += I->second->SourceLineCache != 0;
+    NumFileBytesMapped  += I->second->getSizeBytesMapped();
+  }
+
+  llvm::errs() << NumFileBytesMapped << " bytes of files mapped, "
+               << NumLineNumsComputed << " files with line #'s computed.\n";
+  llvm::errs() << "FileID scans: " << NumLinearScans << " linear, "
+               << NumBinaryProbes << " binary.\n";
+}
+
+ExternalSLocEntrySource::~ExternalSLocEntrySource() { }