tools/clang-cc/PrintPreprocessedOutput.cpp - platform/external/clang - Gitiles

 //===--- PrintPreprocessedOutput.cpp - Implement the -E mode --------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This code simply runs the preprocessor on the input file and prints out the
 // result.  This is the traditional behavior of the -E option.
 //
 //===----------------------------------------------------------------------===//

 #include "clang/Basic/SourceManager.h"
 #include "clang-cc.h"
 #include "clang/Lex/MacroInfo.h"
 #include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Lex/Pragma.h"
 #include "clang/Lex/TokenConcatenation.h"
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/Diagnostic.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/System/Path.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Config/config.h"
 #include "llvm/Support/raw_ostream.h"
 #include <cstdio>
 using namespace clang;

 /// PrintMacroDefinition - Print a macro definition in a form that will be
 /// properly accepted back as a definition.
 static void PrintMacroDefinition(const IdentifierInfo &II, const MacroInfo &MI,
                                  Preprocessor &PP, llvm::raw_ostream &OS) {
   OS << "#define " << II.getName();

   if (MI.isFunctionLike()) {
     OS << '(';
     if (MI.arg_empty())
       ;
     else if (MI.getNumArgs() == 1)
       OS << (*MI.arg_begin())->getName();
     else {
       MacroInfo::arg_iterator AI = MI.arg_begin(), E = MI.arg_end();
       OS << (*AI++)->getName();
       while (AI != E)
         OS << ',' << (*AI++)->getName();
     }

     if (MI.isVariadic()) {
       if (!MI.arg_empty())
         OS << ',';
       OS << "...";
     }
     OS << ')';
   }

   // GCC always emits a space, even if the macro body is empty.  However, do not
   // want to emit two spaces if the first token has a leading space.
   if (MI.tokens_empty() || !MI.tokens_begin()->hasLeadingSpace())
     OS << ' ';

   llvm::SmallVector<char, 128> SpellingBuffer;
   for (MacroInfo::tokens_iterator I = MI.tokens_begin(), E = MI.tokens_end();
        I != E; ++I) {
     if (I->hasLeadingSpace())
       OS << ' ';

     // Make sure we have enough space in the spelling buffer.
     if (I->getLength() < SpellingBuffer.size())
       SpellingBuffer.resize(I->getLength());
     const char *Buffer = &SpellingBuffer[0];
     unsigned SpellingLen = PP.getSpelling(*I, Buffer);
     OS.write(Buffer, SpellingLen);
   }
 }

 //===----------------------------------------------------------------------===//
 // Preprocessed token printer
 //===----------------------------------------------------------------------===//

 static llvm::cl::opt<bool>
 DisableLineMarkers("P", llvm::cl::desc("Disable linemarker output in -E mode"));
 static llvm::cl::opt<bool>
 EnableCommentOutput("C", llvm::cl::desc("Enable comment output in -E mode"));
 static llvm::cl::opt<bool>
 EnableMacroCommentOutput("CC",
                          llvm::cl::desc("Enable comment output in -E mode, "
                                         "even from macro expansions"));
 static llvm::cl::opt<bool>
 DumpMacros("dM", llvm::cl::desc("Print macro definitions in -E mode instead of"
                                 " normal output"));

 static llvm::cl::opt<bool>
 DumpDefines("dD", llvm::cl::desc("Print macro definitions in -E mode in "
                                 "addition to normal output"));

 namespace {
 class PrintPPOutputPPCallbacks : public PPCallbacks {
   Preprocessor &PP;
   TokenConcatenation ConcatInfo;
 public:
   llvm::raw_ostream &OS;
 private:
   unsigned CurLine;
   bool EmittedTokensOnThisLine;
   SrcMgr::CharacteristicKind FileType;
   llvm::SmallString<512> CurFilename;
   bool Initialized;
 public:
   PrintPPOutputPPCallbacks(Preprocessor &pp, llvm::raw_ostream &os)
      : PP(pp), ConcatInfo(PP), OS(os) {
     CurLine = 0;
     CurFilename += "<uninit>";
     EmittedTokensOnThisLine = false;
     FileType = SrcMgr::C_User;
     Initialized = false;
   }

   void SetEmittedTokensOnThisLine() { EmittedTokensOnThisLine = true; }
   bool hasEmittedTokensOnThisLine() const { return EmittedTokensOnThisLine; }

   virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
                            SrcMgr::CharacteristicKind FileType);
   virtual void Ident(SourceLocation Loc, const std::string &str);
   virtual void PragmaComment(SourceLocation Loc, const IdentifierInfo *Kind,
                              const std::string &Str);


   bool HandleFirstTokOnLine(Token &Tok);
   bool MoveToLine(SourceLocation Loc);
   bool AvoidConcat(const Token &PrevTok, const Token &Tok) {
     return ConcatInfo.AvoidConcat(PrevTok, Tok);
   }
   void WriteLineInfo(unsigned LineNo, const char *Extra=0, unsigned ExtraLen=0);

   /// MacroDefined - This hook is called whenever a macro definition is seen.
   void MacroDefined(const IdentifierInfo *II, const MacroInfo *MI);

 };
 }  // end anonymous namespace

 void PrintPPOutputPPCallbacks::WriteLineInfo(unsigned LineNo,
                                              const char *Extra,
                                              unsigned ExtraLen) {
   if (EmittedTokensOnThisLine) {
     OS << '\n';
     EmittedTokensOnThisLine = false;
   }

   OS << '#' << ' ' << LineNo << ' ' << '"';
   OS.write(&CurFilename[0], CurFilename.size());
   OS << '"';

   if (ExtraLen)
     OS.write(Extra, ExtraLen);

   if (FileType == SrcMgr::C_System)
     OS.write(" 3", 2);
   else if (FileType == SrcMgr::C_ExternCSystem)
     OS.write(" 3 4", 4);
   OS << '\n';
 }

 /// MoveToLine - Move the output to the source line specified by the location
 /// object.  We can do this by emitting some number of \n's, or be emitting a
 /// #line directive.  This returns false if already at the specified line, true
 /// if some newlines were emitted.
 bool PrintPPOutputPPCallbacks::MoveToLine(SourceLocation Loc) {
   unsigned LineNo = PP.getSourceManager().getInstantiationLineNumber(Loc);

   if (DisableLineMarkers) {
     if (LineNo == CurLine) return false;

     CurLine = LineNo;

     if (!EmittedTokensOnThisLine)
       return true;

     OS << '\n';
     EmittedTokensOnThisLine = false;
     return true;
   }

   // If this line is "close enough" to the original line, just print newlines,
   // otherwise print a #line directive.
   if (LineNo-CurLine <= 8) {
     if (LineNo-CurLine == 1)
       OS << '\n';
     else if (LineNo == CurLine)
       return false;    // Spelling line moved, but instantiation line didn't.
     else {
       const char *NewLines = "\n\n\n\n\n\n\n\n";
       OS.write(NewLines, LineNo-CurLine);
     }
   } else {
     WriteLineInfo(LineNo, 0, 0);
   }

   CurLine = LineNo;
   return true;
 }


 /// FileChanged - Whenever the preprocessor enters or exits a #include file
 /// it invokes this handler.  Update our conception of the current source
 /// position.
 void PrintPPOutputPPCallbacks::FileChanged(SourceLocation Loc,
                                            FileChangeReason Reason,
                                        SrcMgr::CharacteristicKind NewFileType) {
   // Unless we are exiting a #include, make sure to skip ahead to the line the
   // #include directive was at.
   SourceManager &SourceMgr = PP.getSourceManager();
   if (Reason == PPCallbacks::EnterFile) {
     SourceLocation IncludeLoc = SourceMgr.getPresumedLoc(Loc).getIncludeLoc();
     if (IncludeLoc.isValid())
       MoveToLine(IncludeLoc);
   } else if (Reason == PPCallbacks::SystemHeaderPragma) {
     MoveToLine(Loc);

     // TODO GCC emits the # directive for this directive on the line AFTER the
     // directive and emits a bunch of spaces that aren't needed.  Emulate this
     // strange behavior.
   }

   Loc = SourceMgr.getInstantiationLoc(Loc);
   // FIXME: Should use presumed line #!
   CurLine = SourceMgr.getInstantiationLineNumber(Loc);

   if (DisableLineMarkers) return;

   CurFilename.clear();
   CurFilename += SourceMgr.getPresumedLoc(Loc).getFilename();
   Lexer::Stringify(CurFilename);
   FileType = NewFileType;

   if (!Initialized) {
     WriteLineInfo(CurLine);
     Initialized = true;
   }

   switch (Reason) {
   case PPCallbacks::EnterFile:
     WriteLineInfo(CurLine, " 1", 2);
     break;
   case PPCallbacks::ExitFile:
     WriteLineInfo(CurLine, " 2", 2);
     break;
   case PPCallbacks::SystemHeaderPragma:
   case PPCallbacks::RenameFile:
     WriteLineInfo(CurLine);
     break;
   }
 }

 /// Ident - Handle #ident directives when read by the preprocessor.
 ///
 void PrintPPOutputPPCallbacks::Ident(SourceLocation Loc, const std::string &S) {
   MoveToLine(Loc);

   OS.write("#ident ", strlen("#ident "));
   OS.write(&S[0], S.size());
   EmittedTokensOnThisLine = true;
 }

 /// MacroDefined - This hook is called whenever a macro definition is seen.
 void PrintPPOutputPPCallbacks::MacroDefined(const IdentifierInfo *II,
                                             const MacroInfo *MI) {
   // Only print out macro definitions in -dD mode.
   if (!DumpDefines ||
       // Ignore __FILE__ etc.
       MI->isBuiltinMacro()) return;

   MoveToLine(MI->getDefinitionLoc());
   PrintMacroDefinition(*II, *MI, PP, OS);
 }


 void PrintPPOutputPPCallbacks::PragmaComment(SourceLocation Loc,
                                              const IdentifierInfo *Kind,
                                              const std::string &Str) {
   MoveToLine(Loc);
   OS << "#pragma comment(" << Kind->getName();

   if (!Str.empty()) {
     OS << ", \"";

     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
       unsigned char Char = Str[i];
       if (isprint(Char) && Char != '\\' && Char != '"')
         OS << (char)Char;
       else  // Output anything hard as an octal escape.
         OS << '\\'
            << (char)('0'+ ((Char >> 6) & 7))
            << (char)('0'+ ((Char >> 3) & 7))
            << (char)('0'+ ((Char >> 0) & 7));
     }
     OS << '"';
   }

   OS << ')';
   EmittedTokensOnThisLine = true;
 }


 /// HandleFirstTokOnLine - When emitting a preprocessed file in -E mode, this
 /// is called for the first token on each new line.  If this really is the start
 /// of a new logical line, handle it and return true, otherwise return false.
 /// This may not be the start of a logical line because the "start of line"
 /// marker is set for spelling lines, not instantiation ones.
 bool PrintPPOutputPPCallbacks::HandleFirstTokOnLine(Token &Tok) {
   // Figure out what line we went to and insert the appropriate number of
   // newline characters.
   if (!MoveToLine(Tok.getLocation()))
     return false;

   // Print out space characters so that the first token on a line is
   // indented for easy reading.
   const SourceManager &SourceMgr = PP.getSourceManager();
   unsigned ColNo = SourceMgr.getInstantiationColumnNumber(Tok.getLocation());

   // This hack prevents stuff like:
   // #define HASH #
   // HASH define foo bar
   // From having the # character end up at column 1, which makes it so it
   // is not handled as a #define next time through the preprocessor if in
   // -fpreprocessed mode.
   if (ColNo <= 1 && Tok.is(tok::hash))
     OS << ' ';

   // Otherwise, indent the appropriate number of spaces.
   for (; ColNo > 1; --ColNo)
     OS << ' ';

   return true;
 }

 namespace {
 struct UnknownPragmaHandler : public PragmaHandler {
   const char *Prefix;
   PrintPPOutputPPCallbacks *Callbacks;

   UnknownPragmaHandler(const char *prefix, PrintPPOutputPPCallbacks *callbacks)
     : PragmaHandler(0), Prefix(prefix), Callbacks(callbacks) {}
   virtual void HandlePragma(Preprocessor &PP, Token &PragmaTok) {
     // Figure out what line we went to and insert the appropriate number of
     // newline characters.
     Callbacks->MoveToLine(PragmaTok.getLocation());
     Callbacks->OS.write(Prefix, strlen(Prefix));

     // Read and print all of the pragma tokens.
     while (PragmaTok.isNot(tok::eom)) {
       if (PragmaTok.hasLeadingSpace())
         Callbacks->OS << ' ';
       std::string TokSpell = PP.getSpelling(PragmaTok);
       Callbacks->OS.write(&TokSpell[0], TokSpell.size());
       PP.LexUnexpandedToken(PragmaTok);
     }
     Callbacks->OS << '\n';
   }
 };
 } // end anonymous namespace


 static void PrintPreprocessedTokens(Preprocessor &PP, Token &Tok,
                                     PrintPPOutputPPCallbacks *Callbacks,
                                     llvm::raw_ostream &OS) {
   char Buffer[256];
   Token PrevTok;
   while (1) {

     // If this token is at the start of a line, emit newlines if needed.
     if (Tok.isAtStartOfLine() && Callbacks->HandleFirstTokOnLine(Tok)) {
       // done.
     } else if (Tok.hasLeadingSpace() ||
                // If we haven't emitted a token on this line yet, PrevTok isn't
                // useful to look at and no concatenation could happen anyway.
                (Callbacks->hasEmittedTokensOnThisLine() &&
                 // Don't print "-" next to "-", it would form "--".
                 Callbacks->AvoidConcat(PrevTok, Tok))) {
       OS << ' ';
     }

     if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
       OS.write(II->getName(), II->getLength());
     } else if (Tok.isLiteral() && !Tok.needsCleaning() &&
                Tok.getLiteralData()) {
       OS.write(Tok.getLiteralData(), Tok.getLength());
     } else if (Tok.getLength() < 256) {
       const char *TokPtr = Buffer;
       unsigned Len = PP.getSpelling(Tok, TokPtr);
       OS.write(TokPtr, Len);
     } else {
       std::string S = PP.getSpelling(Tok);
       OS.write(&S[0], S.size());
     }
     Callbacks->SetEmittedTokensOnThisLine();

     if (Tok.is(tok::eof)) break;

     PrevTok = Tok;
     PP.Lex(Tok);
   }
 }

 namespace {
   struct SortMacrosByID {
     typedef std::pair<IdentifierInfo*, MacroInfo*> id_macro_pair;
     bool operator()(const id_macro_pair &LHS, const id_macro_pair &RHS) const {
       return strcmp(LHS.first->getName(), RHS.first->getName()) < 0;
     }
   };
 }

 /// DoPrintPreprocessedInput - This implements -E mode.
 ///
 void clang::DoPrintPreprocessedInput(Preprocessor &PP,
                                      const std::string &OutFile) {
   // Inform the preprocessor whether we want it to retain comments or not, due
   // to -C or -CC.
   PP.SetCommentRetentionState(EnableCommentOutput, EnableMacroCommentOutput);

   // Open the output buffer.
   std::string Err;
   llvm::raw_fd_ostream OS(OutFile.empty() ? "-" : OutFile.c_str(), false, Err);
   if (!Err.empty()) {
     fprintf(stderr, "%s\n", Err.c_str());
     exit(1);
   }

   OS.SetBufferSize(64*1024);

   if (DumpMacros) {
     // -dM mode just scans and ignores all tokens in the files, then dumps out
     // the macro table at the end.
     PP.EnterMainSourceFile();

     Token Tok;
     do PP.Lex(Tok);
     while (Tok.isNot(tok::eof));

     std::vector<std::pair<IdentifierInfo*, MacroInfo*> > MacrosByID;
     for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();
          I != E; ++I)
       MacrosByID.push_back(*I);
     std::sort(MacrosByID.begin(), MacrosByID.end(), SortMacrosByID());

     for (unsigned i = 0, e = MacrosByID.size(); i != e; ++i) {
       MacroInfo &MI = *MacrosByID[i].second;
       // Ignore computed macros like __LINE__ and friends.
       if (MI.isBuiltinMacro()) continue;

       PrintMacroDefinition(*MacrosByID[i].first, MI, PP, OS);
       OS << "\n";
     }

   } else {
     PrintPPOutputPPCallbacks *Callbacks = new PrintPPOutputPPCallbacks(PP, OS);
     PP.AddPragmaHandler(0, new UnknownPragmaHandler("#pragma", Callbacks));
     PP.AddPragmaHandler("GCC", new UnknownPragmaHandler("#pragma GCC",
                                                         Callbacks));

     PP.setPPCallbacks(Callbacks);

     // After we have configured the preprocessor, enter the main file.
     PP.EnterMainSourceFile();

     // Consume all of the tokens that come from the predefines buffer.  Those
     // should not be emitted into the output and are guaranteed to be at the
     // start.
     const SourceManager &SourceMgr = PP.getSourceManager();
     Token Tok;
     do PP.Lex(Tok);
     while (Tok.isNot(tok::eof) && Tok.getLocation().isFileID() &&
            !strcmp(SourceMgr.getPresumedLoc(Tok.getLocation()).getFilename(),
                    "<built-in>"));

     // Read all the preprocessed tokens, printing them out to the stream.
     PrintPreprocessedTokens(PP, Tok, Callbacks, OS);
     OS << '\n';
   }

   // Flush the ostream.
   OS.flush();

   // If an error occurred, remove the output file.
   if (PP.getDiagnostics().hasErrorOccurred() && !OutFile.empty())
     llvm::sys::Path(OutFile).eraseFromDisk();
 }
	//===--- PrintPreprocessedOutput.cpp - Implement the -E mode --------------===//
	//
	// The LLVM Compiler Infrastructure
	//
	// This file is distributed under the University of Illinois Open Source
	// License. See LICENSE.TXT for details.
	//
	//===----------------------------------------------------------------------===//
	//
	// This code simply runs the preprocessor on the input file and prints out the
	// result. This is the traditional behavior of the -E option.
	//
	//===----------------------------------------------------------------------===//

	#include "clang/Basic/SourceManager.h"
	#include "clang-cc.h"
	#include "clang/Lex/MacroInfo.h"
	#include "clang/Lex/PPCallbacks.h"
	#include "clang/Lex/Preprocessor.h"
	#include "clang/Lex/Pragma.h"
	#include "clang/Lex/TokenConcatenation.h"
	#include "clang/Basic/SourceManager.h"
	#include "clang/Basic/Diagnostic.h"
	#include "llvm/ADT/SmallString.h"
	#include "llvm/ADT/StringExtras.h"
	#include "llvm/System/Path.h"
	#include "llvm/Support/CommandLine.h"
	#include "llvm/Config/config.h"
	#include "llvm/Support/raw_ostream.h"
	#include <cstdio>
	using namespace clang;

	/// PrintMacroDefinition - Print a macro definition in a form that will be
	/// properly accepted back as a definition.
	static void PrintMacroDefinition(const IdentifierInfo &II, const MacroInfo &MI,
	Preprocessor &PP, llvm::raw_ostream &OS) {
	OS << "#define " << II.getName();

	if (MI.isFunctionLike()) {
	OS << '(';
	if (MI.arg_empty())
	;
	else if (MI.getNumArgs() == 1)
	OS << (*MI.arg_begin())->getName();
	else {
	MacroInfo::arg_iterator AI = MI.arg_begin(), E = MI.arg_end();
	OS << (*AI++)->getName();
	while (AI != E)
	OS << ',' << (*AI++)->getName();
	}

	if (MI.isVariadic()) {
	if (!MI.arg_empty())
	OS << ',';
	OS << "...";
	}
	OS << ')';
	}

	// GCC always emits a space, even if the macro body is empty. However, do not
	// want to emit two spaces if the first token has a leading space.
	if (MI.tokens_empty() \|\| !MI.tokens_begin()->hasLeadingSpace())
	OS << ' ';

	llvm::SmallVector<char, 128> SpellingBuffer;
	for (MacroInfo::tokens_iterator I = MI.tokens_begin(), E = MI.tokens_end();
	I != E; ++I) {
	if (I->hasLeadingSpace())
	OS << ' ';

	// Make sure we have enough space in the spelling buffer.
	if (I->getLength() < SpellingBuffer.size())
	SpellingBuffer.resize(I->getLength());
	const char *Buffer = &SpellingBuffer[0];
	unsigned SpellingLen = PP.getSpelling(*I, Buffer);
	OS.write(Buffer, SpellingLen);
	}
	}

	//===----------------------------------------------------------------------===//
	// Preprocessed token printer
	//===----------------------------------------------------------------------===//

	static llvm::cl::opt<bool>
	DisableLineMarkers("P", llvm::cl::desc("Disable linemarker output in -E mode"));
	static llvm::cl::opt<bool>
	EnableCommentOutput("C", llvm::cl::desc("Enable comment output in -E mode"));
	static llvm::cl::opt<bool>
	EnableMacroCommentOutput("CC",
	llvm::cl::desc("Enable comment output in -E mode, "
	"even from macro expansions"));
	static llvm::cl::opt<bool>
	DumpMacros("dM", llvm::cl::desc("Print macro definitions in -E mode instead of"
	" normal output"));

	static llvm::cl::opt<bool>
	DumpDefines("dD", llvm::cl::desc("Print macro definitions in -E mode in "
	"addition to normal output"));

	namespace {
	class PrintPPOutputPPCallbacks : public PPCallbacks {
	Preprocessor &PP;
	TokenConcatenation ConcatInfo;
	public:
	llvm::raw_ostream &OS;
	private:
	unsigned CurLine;
	bool EmittedTokensOnThisLine;
	SrcMgr::CharacteristicKind FileType;
	llvm::SmallString<512> CurFilename;
	bool Initialized;
	public:
	PrintPPOutputPPCallbacks(Preprocessor &pp, llvm::raw_ostream &os)
	: PP(pp), ConcatInfo(PP), OS(os) {
	CurLine = 0;
	CurFilename += "<uninit>";
	EmittedTokensOnThisLine = false;
	FileType = SrcMgr::C_User;
	Initialized = false;
	}

	void SetEmittedTokensOnThisLine() { EmittedTokensOnThisLine = true; }
	bool hasEmittedTokensOnThisLine() const { return EmittedTokensOnThisLine; }

	virtual void FileChanged(SourceLocation Loc, FileChangeReason Reason,
	SrcMgr::CharacteristicKind FileType);
	virtual void Ident(SourceLocation Loc, const std::string &str);
	virtual void PragmaComment(SourceLocation Loc, const IdentifierInfo *Kind,
	const std::string &Str);


	bool HandleFirstTokOnLine(Token &Tok);
	bool MoveToLine(SourceLocation Loc);
	bool AvoidConcat(const Token &PrevTok, const Token &Tok) {
	return ConcatInfo.AvoidConcat(PrevTok, Tok);
	}
	void WriteLineInfo(unsigned LineNo, const char *Extra=0, unsigned ExtraLen=0);

	/// MacroDefined - This hook is called whenever a macro definition is seen.
	void MacroDefined(const IdentifierInfo II, const MacroInfo MI);

	};
	} // end anonymous namespace

	void PrintPPOutputPPCallbacks::WriteLineInfo(unsigned LineNo,
	const char *Extra,
	unsigned ExtraLen) {
	if (EmittedTokensOnThisLine) {
	OS << '\n';
	EmittedTokensOnThisLine = false;
	}

	OS << '#' << ' ' << LineNo << ' ' << '"';
	OS.write(&CurFilename[0], CurFilename.size());
	OS << '"';

	if (ExtraLen)
	OS.write(Extra, ExtraLen);

	if (FileType == SrcMgr::C_System)
	OS.write(" 3", 2);
	else if (FileType == SrcMgr::C_ExternCSystem)
	OS.write(" 3 4", 4);
	OS << '\n';
	}

	/// MoveToLine - Move the output to the source line specified by the location
	/// object. We can do this by emitting some number of \n's, or be emitting a
	/// #line directive. This returns false if already at the specified line, true
	/// if some newlines were emitted.
	bool PrintPPOutputPPCallbacks::MoveToLine(SourceLocation Loc) {
	unsigned LineNo = PP.getSourceManager().getInstantiationLineNumber(Loc);

	if (DisableLineMarkers) {
	if (LineNo == CurLine) return false;

	CurLine = LineNo;

	if (!EmittedTokensOnThisLine)
	return true;

	OS << '\n';
	EmittedTokensOnThisLine = false;
	return true;
	}

	// If this line is "close enough" to the original line, just print newlines,
	// otherwise print a #line directive.
	if (LineNo-CurLine <= 8) {
	if (LineNo-CurLine == 1)
	OS << '\n';
	else if (LineNo == CurLine)
	return false; // Spelling line moved, but instantiation line didn't.
	else {
	const char *NewLines = "\n\n\n\n\n\n\n\n";
	OS.write(NewLines, LineNo-CurLine);
	}
	} else {
	WriteLineInfo(LineNo, 0, 0);
	}

	CurLine = LineNo;
	return true;
	}


	/// FileChanged - Whenever the preprocessor enters or exits a #include file
	/// it invokes this handler. Update our conception of the current source
	/// position.
	void PrintPPOutputPPCallbacks::FileChanged(SourceLocation Loc,
	FileChangeReason Reason,
	SrcMgr::CharacteristicKind NewFileType) {
	// Unless we are exiting a #include, make sure to skip ahead to the line the
	// #include directive was at.
	SourceManager &SourceMgr = PP.getSourceManager();
	if (Reason == PPCallbacks::EnterFile) {
	SourceLocation IncludeLoc = SourceMgr.getPresumedLoc(Loc).getIncludeLoc();
	if (IncludeLoc.isValid())
	MoveToLine(IncludeLoc);
	} else if (Reason == PPCallbacks::SystemHeaderPragma) {
	MoveToLine(Loc);

	// TODO GCC emits the # directive for this directive on the line AFTER the
	// directive and emits a bunch of spaces that aren't needed. Emulate this
	// strange behavior.
	}

	Loc = SourceMgr.getInstantiationLoc(Loc);
	// FIXME: Should use presumed line #!
	CurLine = SourceMgr.getInstantiationLineNumber(Loc);

	if (DisableLineMarkers) return;

	CurFilename.clear();
	CurFilename += SourceMgr.getPresumedLoc(Loc).getFilename();
	Lexer::Stringify(CurFilename);
	FileType = NewFileType;

	if (!Initialized) {
	WriteLineInfo(CurLine);
	Initialized = true;
	}

	switch (Reason) {
	case PPCallbacks::EnterFile:
	WriteLineInfo(CurLine, " 1", 2);
	break;
	case PPCallbacks::ExitFile:
	WriteLineInfo(CurLine, " 2", 2);
	break;
	case PPCallbacks::SystemHeaderPragma:
	case PPCallbacks::RenameFile:
	WriteLineInfo(CurLine);
	break;
	}
	}

	/// Ident - Handle #ident directives when read by the preprocessor.
	///
	void PrintPPOutputPPCallbacks::Ident(SourceLocation Loc, const std::string &S) {
	MoveToLine(Loc);

	OS.write("#ident ", strlen("#ident "));
	OS.write(&S[0], S.size());
	EmittedTokensOnThisLine = true;
	}

	/// MacroDefined - This hook is called whenever a macro definition is seen.
	void PrintPPOutputPPCallbacks::MacroDefined(const IdentifierInfo *II,
	const MacroInfo *MI) {
	// Only print out macro definitions in -dD mode.
	if (!DumpDefines \|\|
	// Ignore __FILE__ etc.
	MI->isBuiltinMacro()) return;

	MoveToLine(MI->getDefinitionLoc());
	PrintMacroDefinition(II, MI, PP, OS);
	}


	void PrintPPOutputPPCallbacks::PragmaComment(SourceLocation Loc,
	const IdentifierInfo *Kind,
	const std::string &Str) {
	MoveToLine(Loc);
	OS << "#pragma comment(" << Kind->getName();

	if (!Str.empty()) {
	OS << ", \"";

	for (unsigned i = 0, e = Str.size(); i != e; ++i) {
	unsigned char Char = Str[i];
	if (isprint(Char) && Char != '\\' && Char != '"')
	OS << (char)Char;
	else // Output anything hard as an octal escape.
	OS << '\\'
	<< (char)('0'+ ((Char >> 6) & 7))
	<< (char)('0'+ ((Char >> 3) & 7))
	<< (char)('0'+ ((Char >> 0) & 7));
	}
	OS << '"';
	}

	OS << ')';
	EmittedTokensOnThisLine = true;
	}


	/// HandleFirstTokOnLine - When emitting a preprocessed file in -E mode, this
	/// is called for the first token on each new line. If this really is the start
	/// of a new logical line, handle it and return true, otherwise return false.
	/// This may not be the start of a logical line because the "start of line"
	/// marker is set for spelling lines, not instantiation ones.
	bool PrintPPOutputPPCallbacks::HandleFirstTokOnLine(Token &Tok) {
	// Figure out what line we went to and insert the appropriate number of
	// newline characters.
	if (!MoveToLine(Tok.getLocation()))
	return false;

	// Print out space characters so that the first token on a line is
	// indented for easy reading.
	const SourceManager &SourceMgr = PP.getSourceManager();
	unsigned ColNo = SourceMgr.getInstantiationColumnNumber(Tok.getLocation());

	// This hack prevents stuff like:
	// #define HASH #
	// HASH define foo bar
	// From having the # character end up at column 1, which makes it so it
	// is not handled as a #define next time through the preprocessor if in
	// -fpreprocessed mode.
	if (ColNo <= 1 && Tok.is(tok::hash))
	OS << ' ';

	// Otherwise, indent the appropriate number of spaces.
	for (; ColNo > 1; --ColNo)
	OS << ' ';

	return true;
	}

	namespace {
	struct UnknownPragmaHandler : public PragmaHandler {
	const char *Prefix;
	PrintPPOutputPPCallbacks *Callbacks;

	UnknownPragmaHandler(const char prefix, PrintPPOutputPPCallbacks callbacks)
	: PragmaHandler(0), Prefix(prefix), Callbacks(callbacks) {}
	virtual void HandlePragma(Preprocessor &PP, Token &PragmaTok) {
	// Figure out what line we went to and insert the appropriate number of
	// newline characters.
	Callbacks->MoveToLine(PragmaTok.getLocation());
	Callbacks->OS.write(Prefix, strlen(Prefix));

	// Read and print all of the pragma tokens.
	while (PragmaTok.isNot(tok::eom)) {
	if (PragmaTok.hasLeadingSpace())
	Callbacks->OS << ' ';
	std::string TokSpell = PP.getSpelling(PragmaTok);
	Callbacks->OS.write(&TokSpell[0], TokSpell.size());
	PP.LexUnexpandedToken(PragmaTok);
	}
	Callbacks->OS << '\n';
	}
	};
	} // end anonymous namespace


	static void PrintPreprocessedTokens(Preprocessor &PP, Token &Tok,
	PrintPPOutputPPCallbacks *Callbacks,
	llvm::raw_ostream &OS) {
	char Buffer[256];
	Token PrevTok;
	while (1) {

	// If this token is at the start of a line, emit newlines if needed.
	if (Tok.isAtStartOfLine() && Callbacks->HandleFirstTokOnLine(Tok)) {
	// done.
	} else if (Tok.hasLeadingSpace() \|\|
	// If we haven't emitted a token on this line yet, PrevTok isn't
	// useful to look at and no concatenation could happen anyway.
	(Callbacks->hasEmittedTokensOnThisLine() &&
	// Don't print "-" next to "-", it would form "--".
	Callbacks->AvoidConcat(PrevTok, Tok))) {
	OS << ' ';
	}

	if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
	OS.write(II->getName(), II->getLength());
	} else if (Tok.isLiteral() && !Tok.needsCleaning() &&
	Tok.getLiteralData()) {
	OS.write(Tok.getLiteralData(), Tok.getLength());
	} else if (Tok.getLength() < 256) {
	const char *TokPtr = Buffer;
	unsigned Len = PP.getSpelling(Tok, TokPtr);
	OS.write(TokPtr, Len);
	} else {
	std::string S = PP.getSpelling(Tok);
	OS.write(&S[0], S.size());
	}
	Callbacks->SetEmittedTokensOnThisLine();

	if (Tok.is(tok::eof)) break;

	PrevTok = Tok;
	PP.Lex(Tok);
	}
	}

	namespace {
	struct SortMacrosByID {
	typedef std::pair<IdentifierInfo, MacroInfo> id_macro_pair;
	bool operator()(const id_macro_pair &LHS, const id_macro_pair &RHS) const {
	return strcmp(LHS.first->getName(), RHS.first->getName()) < 0;
	}
	};
	}

	/// DoPrintPreprocessedInput - This implements -E mode.
	///
	void clang::DoPrintPreprocessedInput(Preprocessor &PP,
	const std::string &OutFile) {
	// Inform the preprocessor whether we want it to retain comments or not, due
	// to -C or -CC.
	PP.SetCommentRetentionState(EnableCommentOutput, EnableMacroCommentOutput);

	// Open the output buffer.
	std::string Err;
	llvm::raw_fd_ostream OS(OutFile.empty() ? "-" : OutFile.c_str(), false, Err);
	if (!Err.empty()) {
	fprintf(stderr, "%s\n", Err.c_str());
	exit(1);
	}

	OS.SetBufferSize(64*1024);

	if (DumpMacros) {
	// -dM mode just scans and ignores all tokens in the files, then dumps out
	// the macro table at the end.
	PP.EnterMainSourceFile();

	Token Tok;
	do PP.Lex(Tok);
	while (Tok.isNot(tok::eof));

	std::vector<std::pair<IdentifierInfo, MacroInfo> > MacrosByID;
	for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();
	I != E; ++I)
	MacrosByID.push_back(*I);
	std::sort(MacrosByID.begin(), MacrosByID.end(), SortMacrosByID());

	for (unsigned i = 0, e = MacrosByID.size(); i != e; ++i) {
	MacroInfo &MI = *MacrosByID[i].second;
	// Ignore computed macros like __LINE__ and friends.
	if (MI.isBuiltinMacro()) continue;

	PrintMacroDefinition(*MacrosByID[i].first, MI, PP, OS);
	OS << "\n";
	}

	} else {
	PrintPPOutputPPCallbacks *Callbacks = new PrintPPOutputPPCallbacks(PP, OS);
	PP.AddPragmaHandler(0, new UnknownPragmaHandler("#pragma", Callbacks));
	PP.AddPragmaHandler("GCC", new UnknownPragmaHandler("#pragma GCC",
	Callbacks));

	PP.setPPCallbacks(Callbacks);

	// After we have configured the preprocessor, enter the main file.
	PP.EnterMainSourceFile();

	// Consume all of the tokens that come from the predefines buffer. Those
	// should not be emitted into the output and are guaranteed to be at the
	// start.
	const SourceManager &SourceMgr = PP.getSourceManager();
	Token Tok;
	do PP.Lex(Tok);
	while (Tok.isNot(tok::eof) && Tok.getLocation().isFileID() &&
	!strcmp(SourceMgr.getPresumedLoc(Tok.getLocation()).getFilename(),
	"<built-in>"));

	// Read all the preprocessed tokens, printing them out to the stream.
	PrintPreprocessedTokens(PP, Tok, Callbacks, OS);
	OS << '\n';
	}

	// Flush the ostream.
	OS.flush();

	// If an error occurred, remove the output file.
	if (PP.getDiagnostics().hasErrorOccurred() && !OutFile.empty())
	llvm::sys::Path(OutFile).eraseFromDisk();
	}