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diff --git a/lib/Rewrite/Rewriter.cpp b/lib/Rewrite/Rewriter.cpp
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+//===--- Rewriter.cpp - Code rewriting interface --------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines the Rewriter class, which is used for code
+//  transformations.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/Rewrite/Rewriter.h"
+#include "clang/AST/Stmt.h"
+#include "clang/AST/Decl.h"
+#include "clang/Lex/Lexer.h"
+#include "clang/Basic/SourceManager.h"
+#include "llvm/Support/raw_ostream.h"
+using namespace clang;
+
+void RewriteBuffer::RemoveText(unsigned OrigOffset, unsigned Size) {
+  // Nothing to remove, exit early.
+  if (Size == 0) return;
+
+  unsigned RealOffset = getMappedOffset(OrigOffset, true);
+  assert(RealOffset+Size < Buffer.size() && "Invalid location");
+  
+  // Remove the dead characters.
+  Buffer.erase(RealOffset, Size);
+
+  // Add a delta so that future changes are offset correctly.
+  AddReplaceDelta(OrigOffset, -Size);
+}
+
+void RewriteBuffer::InsertText(unsigned OrigOffset,
+                               const char *StrData, unsigned StrLen,
+                               bool InsertAfter) {
+  
+  // Nothing to insert, exit early.
+  if (StrLen == 0) return;
+
+  unsigned RealOffset = getMappedOffset(OrigOffset, InsertAfter);
+  Buffer.insert(RealOffset, StrData, StrData+StrLen);
+  
+  // Add a delta so that future changes are offset correctly.
+  AddInsertDelta(OrigOffset, StrLen);
+}
+
+/// ReplaceText - This method replaces a range of characters in the input
+/// buffer with a new string.  This is effectively a combined "remove+insert"
+/// operation.
+void RewriteBuffer::ReplaceText(unsigned OrigOffset, unsigned OrigLength,
+                                const char *NewStr, unsigned NewLength) {
+  unsigned RealOffset = getMappedOffset(OrigOffset, true);
+  Buffer.erase(RealOffset, OrigLength);
+  Buffer.insert(RealOffset, NewStr, NewStr+NewLength);
+  if (OrigLength != NewLength)
+    AddReplaceDelta(OrigOffset, NewLength-OrigLength);
+}
+
+
+//===----------------------------------------------------------------------===//
+// Rewriter class
+//===----------------------------------------------------------------------===//
+
+/// getRangeSize - Return the size in bytes of the specified range if they
+/// are in the same file.  If not, this returns -1.
+int Rewriter::getRangeSize(SourceRange Range) const {
+  if (!isRewritable(Range.getBegin()) ||
+      !isRewritable(Range.getEnd())) return -1;
+  
+  FileID StartFileID, EndFileID;
+  unsigned StartOff, EndOff;
+  
+  StartOff = getLocationOffsetAndFileID(Range.getBegin(), StartFileID);
+  EndOff   = getLocationOffsetAndFileID(Range.getEnd(), EndFileID);
+  
+  if (StartFileID != EndFileID)
+    return -1;
+  
+  // If edits have been made to this buffer, the delta between the range may
+  // have changed.
+  std::map<FileID, RewriteBuffer>::const_iterator I =
+    RewriteBuffers.find(StartFileID);
+  if (I != RewriteBuffers.end()) {
+    const RewriteBuffer &RB = I->second;
+    EndOff = RB.getMappedOffset(EndOff, true);
+    StartOff = RB.getMappedOffset(StartOff);
+  }
+
+  
+  // Adjust the end offset to the end of the last token, instead of being the
+  // start of the last token.
+  EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+  
+  return EndOff-StartOff;
+}
+
+/// getRewritenText - Return the rewritten form of the text in the specified
+/// range.  If the start or end of the range was unrewritable or if they are
+/// in different buffers, this returns an empty string. 
+///
+/// Note that this method is not particularly efficient.
+///
+std::string Rewriter::getRewritenText(SourceRange Range) const {
+  if (!isRewritable(Range.getBegin()) ||
+      !isRewritable(Range.getEnd()))
+    return "";
+  
+  FileID StartFileID, EndFileID;
+  unsigned StartOff, EndOff;
+  StartOff = getLocationOffsetAndFileID(Range.getBegin(), StartFileID);
+  EndOff   = getLocationOffsetAndFileID(Range.getEnd(), EndFileID);
+  
+  if (StartFileID != EndFileID)
+    return ""; // Start and end in different buffers.
+  
+  // If edits have been made to this buffer, the delta between the range may
+  // have changed.
+  std::map<FileID, RewriteBuffer>::const_iterator I =
+    RewriteBuffers.find(StartFileID);
+  if (I == RewriteBuffers.end()) {
+    // If the buffer hasn't been rewritten, just return the text from the input.
+    const char *Ptr = SourceMgr->getCharacterData(Range.getBegin());
+    
+    // Adjust the end offset to the end of the last token, instead of being the
+    // start of the last token.
+    EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+    return std::string(Ptr, Ptr+EndOff-StartOff);
+  }
+  
+  const RewriteBuffer &RB = I->second;
+  EndOff = RB.getMappedOffset(EndOff, true);
+  StartOff = RB.getMappedOffset(StartOff);
+  
+  // Adjust the end offset to the end of the last token, instead of being the
+  // start of the last token.
+  EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);
+
+  // Advance the iterators to the right spot, yay for linear time algorithms.
+  RewriteBuffer::iterator Start = RB.begin();
+  std::advance(Start, StartOff);
+  RewriteBuffer::iterator End = Start;
+  std::advance(End, EndOff-StartOff);
+  
+  return std::string(Start, End);
+}
+
+unsigned Rewriter::getLocationOffsetAndFileID(SourceLocation Loc,
+                                              FileID &FID) const {
+  assert(Loc.isValid() && "Invalid location");
+  std::pair<FileID,unsigned> V = SourceMgr->getDecomposedLoc(Loc);
+  FID = V.first;
+  return V.second;
+}
+
+
+/// getEditBuffer - Get or create a RewriteBuffer for the specified FileID.
+///
+RewriteBuffer &Rewriter::getEditBuffer(FileID FID) {
+  std::map<FileID, RewriteBuffer>::iterator I =
+    RewriteBuffers.lower_bound(FID);
+  if (I != RewriteBuffers.end() && I->first == FID) 
+    return I->second;
+  I = RewriteBuffers.insert(I, std::make_pair(FID, RewriteBuffer()));
+  
+  std::pair<const char*, const char*> MB = SourceMgr->getBufferData(FID);
+  I->second.Initialize(MB.first, MB.second);
+  
+  return I->second;
+}
+
+/// InsertText - Insert the specified string at the specified location in the
+/// original buffer.
+bool Rewriter::InsertText(SourceLocation Loc, const char *StrData,
+                          unsigned StrLen, bool InsertAfter) {
+  if (!isRewritable(Loc)) return true;
+  FileID FID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
+  getEditBuffer(FID).InsertText(StartOffs, StrData, StrLen, InsertAfter);
+  return false;
+}
+
+/// RemoveText - Remove the specified text region.
+bool Rewriter::RemoveText(SourceLocation Start, unsigned Length) {
+  if (!isRewritable(Start)) return true;
+  FileID FID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Start, FID);
+  getEditBuffer(FID).RemoveText(StartOffs, Length);
+  return false;
+}
+
+/// ReplaceText - This method replaces a range of characters in the input
+/// buffer with a new string.  This is effectively a combined "remove/insert"
+/// operation.
+bool Rewriter::ReplaceText(SourceLocation Start, unsigned OrigLength,
+                           const char *NewStr, unsigned NewLength) {
+  if (!isRewritable(Start)) return true;
+  FileID StartFileID;
+  unsigned StartOffs = getLocationOffsetAndFileID(Start, StartFileID);
+  
+  getEditBuffer(StartFileID).ReplaceText(StartOffs, OrigLength,
+                                         NewStr, NewLength);
+  return false;
+}
+
+/// ReplaceStmt - This replaces a Stmt/Expr with another, using the pretty
+/// printer to generate the replacement code.  This returns true if the input
+/// could not be rewritten, or false if successful.
+bool Rewriter::ReplaceStmt(Stmt *From, Stmt *To) {
+  // Measaure the old text.
+  int Size = getRangeSize(From->getSourceRange());
+  if (Size == -1)
+    return true;
+  
+  // Get the new text.
+  std::string SStr;
+  llvm::raw_string_ostream S(SStr);
+  To->printPretty(S);
+  const std::string &Str = S.str();
+
+  ReplaceText(From->getLocStart(), Size, &Str[0], Str.size());
+  return false;
+}
+
+