lib/Rewrite/Rewriter.cpp - platform/external/clang - Gitiles

 //===--- 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/Basic/DiagnosticIDs.h"
 #include "clang/Basic/FileManager.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Lex/Lexer.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/FileSystem.h"
 using namespace clang;

 raw_ostream &RewriteBuffer::write(raw_ostream &os) const {
   // FIXME: eliminate the copy by writing out each chunk at a time
   os << std::string(begin(), end());
   return os;
 }

 /// \brief Return true if this character is non-new-line whitespace:
 /// ' ', '\t', '\f', '\v', '\r'.
 static inline bool isWhitespace(unsigned char c) {
   switch (c) {
   case ' ':
   case '\t':
   case '\f':
   case '\v':
   case '\r':
     return true;
   default:
     return false;
   }
 }

 void RewriteBuffer::RemoveText(unsigned OrigOffset, unsigned Size,
                                bool removeLineIfEmpty) {
   // 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);

   if (removeLineIfEmpty) {
     // Find the line that the remove occurred and if it is completely empty
     // remove the line as well.

     iterator curLineStart = begin();
     unsigned curLineStartOffs = 0;
     iterator posI = begin();
     for (unsigned i = 0; i != RealOffset; ++i) {
       if (*posI == '\n') {
         curLineStart = posI;
         ++curLineStart;
         curLineStartOffs = i + 1;
       }
       ++posI;
     }

     unsigned lineSize = 0;
     posI = curLineStart;
     while (posI != end() && isWhitespace(*posI)) {
       ++posI;
       ++lineSize;
     }
     if (posI != end() && *posI == '\n') {
       Buffer.erase(curLineStartOffs, lineSize + 1/* + '\n'*/);
       AddReplaceDelta(curLineStartOffs, -(lineSize + 1/* + '\n'*/));
     }
   }
 }

 void RewriteBuffer::InsertText(unsigned OrigOffset, StringRef Str,
                                bool InsertAfter) {

   // Nothing to insert, exit early.
   if (Str.empty()) return;

   unsigned RealOffset = getMappedOffset(OrigOffset, InsertAfter);
   Buffer.insert(RealOffset, Str.begin(), Str.end());

   // Add a delta so that future changes are offset correctly.
   AddInsertDelta(OrigOffset, Str.size());
 }

 /// 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,
                                 StringRef NewStr) {
   unsigned RealOffset = getMappedOffset(OrigOffset, true);
   Buffer.erase(RealOffset, OrigLength);
   Buffer.insert(RealOffset, NewStr.begin(), NewStr.end());
   if (OrigLength != NewStr.size())
     AddReplaceDelta(OrigOffset, NewStr.size() - 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(const CharSourceRange &Range,
                            RewriteOptions opts) 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, opts.IncludeInsertsAtEndOfRange);
     StartOff = RB.getMappedOffset(StartOff, !opts.IncludeInsertsAtBeginOfRange);
   }


   // Adjust the end offset to the end of the last token, instead of being the
   // start of the last token if this is a token range.
   if (Range.isTokenRange())
     EndOff += Lexer::MeasureTokenLength(Range.getEnd(), *SourceMgr, *LangOpts);

   return EndOff-StartOff;
 }

 int Rewriter::getRangeSize(SourceRange Range, RewriteOptions opts) const {
   return getRangeSize(CharSourceRange::getTokenRange(Range), opts);
 }


 /// getRewrittenText - 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::getRewrittenText(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()));

   StringRef MB = SourceMgr->getBufferData(FID);
   I->second.Initialize(MB.begin(), MB.end());

   return I->second;
 }

 /// InsertText - Insert the specified string at the specified location in the
 /// original buffer.
 bool Rewriter::InsertText(SourceLocation Loc, StringRef Str,
                           bool InsertAfter, bool indentNewLines) {
   if (!isRewritable(Loc)) return true;
   FileID FID;
   unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);

   SmallString<128> indentedStr;
   if (indentNewLines && Str.find('\n') != StringRef::npos) {
     StringRef MB = SourceMgr->getBufferData(FID);

     unsigned lineNo = SourceMgr->getLineNumber(FID, StartOffs) - 1;
     const SrcMgr::ContentCache *
         Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();
     unsigned lineOffs = Content->SourceLineCache[lineNo];

     // Find the whitespace at the start of the line.
     StringRef indentSpace;
     {
       unsigned i = lineOffs;
       while (isWhitespace(MB[i]))
         ++i;
       indentSpace = MB.substr(lineOffs, i-lineOffs);
     }

     SmallVector<StringRef, 4> lines;
     Str.split(lines, "\n");

     for (unsigned i = 0, e = lines.size(); i != e; ++i) {
       indentedStr += lines[i];
       if (i < e-1) {
         indentedStr += '\n';
         indentedStr += indentSpace;
       }
     }
     Str = indentedStr.str();
   }

   getEditBuffer(FID).InsertText(StartOffs, Str, InsertAfter);
   return false;
 }

 bool Rewriter::InsertTextAfterToken(SourceLocation Loc, StringRef Str) {
   if (!isRewritable(Loc)) return true;
   FileID FID;
   unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
   RewriteOptions rangeOpts;
   rangeOpts.IncludeInsertsAtBeginOfRange = false;
   StartOffs += getRangeSize(SourceRange(Loc, Loc), rangeOpts);
   getEditBuffer(FID).InsertText(StartOffs, Str, /*InsertAfter*/true);
   return false;
 }

 /// RemoveText - Remove the specified text region.
 bool Rewriter::RemoveText(SourceLocation Start, unsigned Length,
                           RewriteOptions opts) {
   if (!isRewritable(Start)) return true;
   FileID FID;
   unsigned StartOffs = getLocationOffsetAndFileID(Start, FID);
   getEditBuffer(FID).RemoveText(StartOffs, Length, opts.RemoveLineIfEmpty);
   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,
                            StringRef NewStr) {
   if (!isRewritable(Start)) return true;
   FileID StartFileID;
   unsigned StartOffs = getLocationOffsetAndFileID(Start, StartFileID);

   getEditBuffer(StartFileID).ReplaceText(StartOffs, OrigLength, NewStr);
   return false;
 }

 bool Rewriter::ReplaceText(SourceRange range, SourceRange replacementRange) {
   if (!isRewritable(range.getBegin())) return true;
   if (!isRewritable(range.getEnd())) return true;
   if (replacementRange.isInvalid()) return true;
   SourceLocation start = range.getBegin();
   unsigned origLength = getRangeSize(range);
   unsigned newLength = getRangeSize(replacementRange);
   FileID FID;
   unsigned newOffs = getLocationOffsetAndFileID(replacementRange.getBegin(),
                                                 FID);
   StringRef MB = SourceMgr->getBufferData(FID);
   return ReplaceText(start, origLength, MB.substr(newOffs, newLength));
 }

 /// 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, 0, PrintingPolicy(*LangOpts));
   const std::string &Str = S.str();

   ReplaceText(From->getLocStart(), Size, Str);
   return false;
 }

 std::string Rewriter::ConvertToString(Stmt *From) {
   std::string SStr;
   llvm::raw_string_ostream S(SStr);
   From->printPretty(S, 0, PrintingPolicy(*LangOpts));
   return S.str();
 }

 bool Rewriter::IncreaseIndentation(CharSourceRange range,
                                    SourceLocation parentIndent) {
   if (range.isInvalid()) return true;
   if (!isRewritable(range.getBegin())) return true;
   if (!isRewritable(range.getEnd())) return true;
   if (!isRewritable(parentIndent)) return true;

   FileID StartFileID, EndFileID, parentFileID;
   unsigned StartOff, EndOff, parentOff;

   StartOff = getLocationOffsetAndFileID(range.getBegin(), StartFileID);
   EndOff   = getLocationOffsetAndFileID(range.getEnd(), EndFileID);
   parentOff = getLocationOffsetAndFileID(parentIndent, parentFileID);

   if (StartFileID != EndFileID || StartFileID != parentFileID)
     return true;
   if (StartOff > EndOff)
     return true;

   FileID FID = StartFileID;
   StringRef MB = SourceMgr->getBufferData(FID);

   unsigned parentLineNo = SourceMgr->getLineNumber(FID, parentOff) - 1;
   unsigned startLineNo = SourceMgr->getLineNumber(FID, StartOff) - 1;
   unsigned endLineNo = SourceMgr->getLineNumber(FID, EndOff) - 1;

   const SrcMgr::ContentCache *
       Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();

   // Find where the lines start.
   unsigned parentLineOffs = Content->SourceLineCache[parentLineNo];
   unsigned startLineOffs = Content->SourceLineCache[startLineNo];

   // Find the whitespace at the start of each line.
   StringRef parentSpace, startSpace;
   {
     unsigned i = parentLineOffs;
     while (isWhitespace(MB[i]))
       ++i;
     parentSpace = MB.substr(parentLineOffs, i-parentLineOffs);

     i = startLineOffs;
     while (isWhitespace(MB[i]))
       ++i;
     startSpace = MB.substr(startLineOffs, i-startLineOffs);
   }
   if (parentSpace.size() >= startSpace.size())
     return true;
   if (!startSpace.startswith(parentSpace))
     return true;

   StringRef indent = startSpace.substr(parentSpace.size());

   // Indent the lines between start/end offsets.
   RewriteBuffer &RB = getEditBuffer(FID);
   for (unsigned lineNo = startLineNo; lineNo <= endLineNo; ++lineNo) {
     unsigned offs = Content->SourceLineCache[lineNo];
     unsigned i = offs;
     while (isWhitespace(MB[i]))
       ++i;
     StringRef origIndent = MB.substr(offs, i-offs);
     if (origIndent.startswith(startSpace))
       RB.InsertText(offs, indent, /*InsertAfter=*/false);
   }

   return false;
 }

 // A wrapper for a file stream that atomically overwrites the target.
 //
 // Creates a file output stream for a temporary file in the constructor,
 // which is later accessible via getStream() if ok() return true.
 // Flushes the stream and moves the temporary file to the target location
 // in the destructor.
 class AtomicallyMovedFile {
 public:
   AtomicallyMovedFile(DiagnosticsEngine &Diagnostics, StringRef Filename,
                       bool &AllWritten)
     : Diagnostics(Diagnostics), Filename(Filename), AllWritten(AllWritten) {
     TempFilename = Filename;
     TempFilename += "-%%%%%%%%";
     int FD;
     if (llvm::sys::fs::unique_file(TempFilename.str(), FD, TempFilename,
                                     /*makeAbsolute=*/true, 0664)) {
       AllWritten = false;
       Diagnostics.Report(clang::diag::err_unable_to_make_temp)
         << TempFilename;
     } else {
       FileStream.reset(new llvm::raw_fd_ostream(FD, /*shouldClose=*/true));
     }
   }

   ~AtomicallyMovedFile() {
     if (!ok()) return;

     FileStream->flush();
 #ifdef _WIN32
     // Win32 does not allow rename/removing opened files.
     FileStream.reset();
 #endif
     if (llvm::error_code ec =
           llvm::sys::fs::rename(TempFilename.str(), Filename)) {
       AllWritten = false;
       Diagnostics.Report(clang::diag::err_unable_to_rename_temp)
         << TempFilename << Filename << ec.message();
       bool existed;
       // If the remove fails, there's not a lot we can do - this is already an
       // error.
       llvm::sys::fs::remove(TempFilename.str(), existed);
     }
   }

   bool ok() { return FileStream; }
   llvm::raw_ostream &getStream() { return *FileStream; }

 private:
   DiagnosticsEngine &Diagnostics;
   StringRef Filename;
   SmallString<128> TempFilename;
   OwningPtr<llvm::raw_fd_ostream> FileStream;
   bool &AllWritten;
 };

 bool Rewriter::overwriteChangedFiles() {
   bool AllWritten = true;
   for (buffer_iterator I = buffer_begin(), E = buffer_end(); I != E; ++I) {
     const FileEntry *Entry =
         getSourceMgr().getFileEntryForID(I->first);
     AtomicallyMovedFile File(getSourceMgr().getDiagnostics(), Entry->getName(),
                              AllWritten);
     if (File.ok()) {
       I->second.write(File.getStream());
     }
   }
   return !AllWritten;
 }
	//===--- 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/Basic/DiagnosticIDs.h"
	#include "clang/Basic/FileManager.h"
	#include "clang/Basic/SourceManager.h"
	#include "clang/Lex/Lexer.h"
	#include "llvm/ADT/SmallString.h"
	#include "llvm/Support/FileSystem.h"
	using namespace clang;

	raw_ostream &RewriteBuffer::write(raw_ostream &os) const {
	// FIXME: eliminate the copy by writing out each chunk at a time
	os << std::string(begin(), end());
	return os;
	}

	/// \brief Return true if this character is non-new-line whitespace:
	/// ' ', '\t', '\f', '\v', '\r'.
	static inline bool isWhitespace(unsigned char c) {
	switch (c) {
	case ' ':
	case '\t':
	case '\f':
	case '\v':
	case '\r':
	return true;
	default:
	return false;
	}
	}

	void RewriteBuffer::RemoveText(unsigned OrigOffset, unsigned Size,
	bool removeLineIfEmpty) {
	// 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);

	if (removeLineIfEmpty) {
	// Find the line that the remove occurred and if it is completely empty
	// remove the line as well.

	iterator curLineStart = begin();
	unsigned curLineStartOffs = 0;
	iterator posI = begin();
	for (unsigned i = 0; i != RealOffset; ++i) {
	if (*posI == '\n') {
	curLineStart = posI;
	++curLineStart;
	curLineStartOffs = i + 1;
	}
	++posI;
	}

	unsigned lineSize = 0;
	posI = curLineStart;
	while (posI != end() && isWhitespace(*posI)) {
	++posI;
	++lineSize;
	}
	if (posI != end() && *posI == '\n') {
	Buffer.erase(curLineStartOffs, lineSize + 1/* + '\n'*/);
	AddReplaceDelta(curLineStartOffs, -(lineSize + 1/* + '\n'*/));
	}
	}
	}

	void RewriteBuffer::InsertText(unsigned OrigOffset, StringRef Str,
	bool InsertAfter) {

	// Nothing to insert, exit early.
	if (Str.empty()) return;

	unsigned RealOffset = getMappedOffset(OrigOffset, InsertAfter);
	Buffer.insert(RealOffset, Str.begin(), Str.end());

	// Add a delta so that future changes are offset correctly.
	AddInsertDelta(OrigOffset, Str.size());
	}

	/// 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,
	StringRef NewStr) {
	unsigned RealOffset = getMappedOffset(OrigOffset, true);
	Buffer.erase(RealOffset, OrigLength);
	Buffer.insert(RealOffset, NewStr.begin(), NewStr.end());
	if (OrigLength != NewStr.size())
	AddReplaceDelta(OrigOffset, NewStr.size() - 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(const CharSourceRange &Range,
	RewriteOptions opts) 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, opts.IncludeInsertsAtEndOfRange);
	StartOff = RB.getMappedOffset(StartOff, !opts.IncludeInsertsAtBeginOfRange);
	}


	// Adjust the end offset to the end of the last token, instead of being the
	// start of the last token if this is a token range.
	if (Range.isTokenRange())
	EndOff += Lexer::MeasureTokenLength(Range.getEnd(), SourceMgr, LangOpts);

	return EndOff-StartOff;
	}

	int Rewriter::getRangeSize(SourceRange Range, RewriteOptions opts) const {
	return getRangeSize(CharSourceRange::getTokenRange(Range), opts);
	}


	/// getRewrittenText - 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::getRewrittenText(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()));

	StringRef MB = SourceMgr->getBufferData(FID);
	I->second.Initialize(MB.begin(), MB.end());

	return I->second;
	}

	/// InsertText - Insert the specified string at the specified location in the
	/// original buffer.
	bool Rewriter::InsertText(SourceLocation Loc, StringRef Str,
	bool InsertAfter, bool indentNewLines) {
	if (!isRewritable(Loc)) return true;
	FileID FID;
	unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);

	SmallString<128> indentedStr;
	if (indentNewLines && Str.find('\n') != StringRef::npos) {
	StringRef MB = SourceMgr->getBufferData(FID);

	unsigned lineNo = SourceMgr->getLineNumber(FID, StartOffs) - 1;
	const SrcMgr::ContentCache *
	Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();
	unsigned lineOffs = Content->SourceLineCache[lineNo];

	// Find the whitespace at the start of the line.
	StringRef indentSpace;
	{
	unsigned i = lineOffs;
	while (isWhitespace(MB[i]))
	++i;
	indentSpace = MB.substr(lineOffs, i-lineOffs);
	}

	SmallVector<StringRef, 4> lines;
	Str.split(lines, "\n");

	for (unsigned i = 0, e = lines.size(); i != e; ++i) {
	indentedStr += lines[i];
	if (i < e-1) {
	indentedStr += '\n';
	indentedStr += indentSpace;
	}
	}
	Str = indentedStr.str();
	}

	getEditBuffer(FID).InsertText(StartOffs, Str, InsertAfter);
	return false;
	}

	bool Rewriter::InsertTextAfterToken(SourceLocation Loc, StringRef Str) {
	if (!isRewritable(Loc)) return true;
	FileID FID;
	unsigned StartOffs = getLocationOffsetAndFileID(Loc, FID);
	RewriteOptions rangeOpts;
	rangeOpts.IncludeInsertsAtBeginOfRange = false;
	StartOffs += getRangeSize(SourceRange(Loc, Loc), rangeOpts);
	getEditBuffer(FID).InsertText(StartOffs, Str, /InsertAfter/true);
	return false;
	}

	/// RemoveText - Remove the specified text region.
	bool Rewriter::RemoveText(SourceLocation Start, unsigned Length,
	RewriteOptions opts) {
	if (!isRewritable(Start)) return true;
	FileID FID;
	unsigned StartOffs = getLocationOffsetAndFileID(Start, FID);
	getEditBuffer(FID).RemoveText(StartOffs, Length, opts.RemoveLineIfEmpty);
	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,
	StringRef NewStr) {
	if (!isRewritable(Start)) return true;
	FileID StartFileID;
	unsigned StartOffs = getLocationOffsetAndFileID(Start, StartFileID);

	getEditBuffer(StartFileID).ReplaceText(StartOffs, OrigLength, NewStr);
	return false;
	}

	bool Rewriter::ReplaceText(SourceRange range, SourceRange replacementRange) {
	if (!isRewritable(range.getBegin())) return true;
	if (!isRewritable(range.getEnd())) return true;
	if (replacementRange.isInvalid()) return true;
	SourceLocation start = range.getBegin();
	unsigned origLength = getRangeSize(range);
	unsigned newLength = getRangeSize(replacementRange);
	FileID FID;
	unsigned newOffs = getLocationOffsetAndFileID(replacementRange.getBegin(),
	FID);
	StringRef MB = SourceMgr->getBufferData(FID);
	return ReplaceText(start, origLength, MB.substr(newOffs, newLength));
	}

	/// 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, 0, PrintingPolicy(*LangOpts));
	const std::string &Str = S.str();

	ReplaceText(From->getLocStart(), Size, Str);
	return false;
	}

	std::string Rewriter::ConvertToString(Stmt *From) {
	std::string SStr;
	llvm::raw_string_ostream S(SStr);
	From->printPretty(S, 0, PrintingPolicy(*LangOpts));
	return S.str();
	}

	bool Rewriter::IncreaseIndentation(CharSourceRange range,
	SourceLocation parentIndent) {
	if (range.isInvalid()) return true;
	if (!isRewritable(range.getBegin())) return true;
	if (!isRewritable(range.getEnd())) return true;
	if (!isRewritable(parentIndent)) return true;

	FileID StartFileID, EndFileID, parentFileID;
	unsigned StartOff, EndOff, parentOff;

	StartOff = getLocationOffsetAndFileID(range.getBegin(), StartFileID);
	EndOff = getLocationOffsetAndFileID(range.getEnd(), EndFileID);
	parentOff = getLocationOffsetAndFileID(parentIndent, parentFileID);

	if (StartFileID != EndFileID \|\| StartFileID != parentFileID)
	return true;
	if (StartOff > EndOff)
	return true;

	FileID FID = StartFileID;
	StringRef MB = SourceMgr->getBufferData(FID);

	unsigned parentLineNo = SourceMgr->getLineNumber(FID, parentOff) - 1;
	unsigned startLineNo = SourceMgr->getLineNumber(FID, StartOff) - 1;
	unsigned endLineNo = SourceMgr->getLineNumber(FID, EndOff) - 1;

	const SrcMgr::ContentCache *
	Content = SourceMgr->getSLocEntry(FID).getFile().getContentCache();

	// Find where the lines start.
	unsigned parentLineOffs = Content->SourceLineCache[parentLineNo];
	unsigned startLineOffs = Content->SourceLineCache[startLineNo];

	// Find the whitespace at the start of each line.
	StringRef parentSpace, startSpace;
	{
	unsigned i = parentLineOffs;
	while (isWhitespace(MB[i]))
	++i;
	parentSpace = MB.substr(parentLineOffs, i-parentLineOffs);

	i = startLineOffs;
	while (isWhitespace(MB[i]))
	++i;
	startSpace = MB.substr(startLineOffs, i-startLineOffs);
	}
	if (parentSpace.size() >= startSpace.size())
	return true;
	if (!startSpace.startswith(parentSpace))
	return true;

	StringRef indent = startSpace.substr(parentSpace.size());

	// Indent the lines between start/end offsets.
	RewriteBuffer &RB = getEditBuffer(FID);
	for (unsigned lineNo = startLineNo; lineNo <= endLineNo; ++lineNo) {
	unsigned offs = Content->SourceLineCache[lineNo];
	unsigned i = offs;
	while (isWhitespace(MB[i]))
	++i;
	StringRef origIndent = MB.substr(offs, i-offs);
	if (origIndent.startswith(startSpace))
	RB.InsertText(offs, indent, /InsertAfter=/false);
	}

	return false;
	}

	// A wrapper for a file stream that atomically overwrites the target.
	//
	// Creates a file output stream for a temporary file in the constructor,
	// which is later accessible via getStream() if ok() return true.
	// Flushes the stream and moves the temporary file to the target location
	// in the destructor.
	class AtomicallyMovedFile {
	public:
	AtomicallyMovedFile(DiagnosticsEngine &Diagnostics, StringRef Filename,
	bool &AllWritten)
	: Diagnostics(Diagnostics), Filename(Filename), AllWritten(AllWritten) {
	TempFilename = Filename;
	TempFilename += "-%%%%%%%%";
	int FD;
	if (llvm::sys::fs::unique_file(TempFilename.str(), FD, TempFilename,
	/makeAbsolute=/true, 0664)) {
	AllWritten = false;
	Diagnostics.Report(clang::diag::err_unable_to_make_temp)
	<< TempFilename;
	} else {
	FileStream.reset(new llvm::raw_fd_ostream(FD, /shouldClose=/true));
	}
	}

	~AtomicallyMovedFile() {
	if (!ok()) return;

	FileStream->flush();
	#ifdef _WIN32
	// Win32 does not allow rename/removing opened files.
	FileStream.reset();
	#endif
	if (llvm::error_code ec =
	llvm::sys::fs::rename(TempFilename.str(), Filename)) {
	AllWritten = false;
	Diagnostics.Report(clang::diag::err_unable_to_rename_temp)
	<< TempFilename << Filename << ec.message();
	bool existed;
	// If the remove fails, there's not a lot we can do - this is already an
	// error.
	llvm::sys::fs::remove(TempFilename.str(), existed);
	}
	}

	bool ok() { return FileStream; }
	llvm::raw_ostream &getStream() { return *FileStream; }

	private:
	DiagnosticsEngine &Diagnostics;
	StringRef Filename;
	SmallString<128> TempFilename;
	OwningPtr<llvm::raw_fd_ostream> FileStream;
	bool &AllWritten;
	};

	bool Rewriter::overwriteChangedFiles() {
	bool AllWritten = true;
	for (buffer_iterator I = buffer_begin(), E = buffer_end(); I != E; ++I) {
	const FileEntry *Entry =
	getSourceMgr().getFileEntryForID(I->first);
	AtomicallyMovedFile File(getSourceMgr().getDiagnostics(), Entry->getName(),
	AllWritten);
	if (File.ok()) {
	I->second.write(File.getStream());
	}
	}
	return !AllWritten;
	}