//===--- PrintPreprocessedOutput.cpp - Implement the -E mode --------------===//

//

// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.

// See https://llvm.org/LICENSE.txt for license information.

// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

//

//===----------------------------------------------------------------------===//

//

// 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/Frontend/Utils.h"

#include "clang/Basic/CharInfo.h"

#include "clang/Basic/Diagnostic.h"

#include "clang/Basic/SourceManager.h"

#include "clang/Frontend/PreprocessorOutputOptions.h"

#include "clang/Lex/MacroInfo.h"

#include "clang/Lex/PPCallbacks.h"

#include "clang/Lex/Pragma.h"

#include "clang/Lex/Preprocessor.h"

#include "clang/Lex/TokenConcatenation.h"

#include "llvm/ADT/STLExtras.h"

#include "llvm/ADT/SmallString.h"

#include "llvm/ADT/StringRef.h"

#include "llvm/Support/ErrorHandling.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, raw_ostream &OS) {

  OS << "#define " << II.getName();

  if (MI.isFunctionLike()) {

    OS << '(';

    if (!MI.param_empty()) {

      MacroInfo::param_iterator AI = MI.param_begin(), E = MI.param_end();

      for (; AI+1 != E; 
++AI3
) {

        OS << (*AI)->getName();

        OS << ',';

      }

      // Last argument.

      if ((*AI)->getName() == "__VA_ARGS__")

        OS << "...";

      else

        OS << (*AI)->getName();

    }

    if (MI.isGNUVarargs())

      OS << "...";  // #define foo(x...)

    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()458k
)

    OS << ' ';

  SmallString<128> SpellingBuffer;

  for (const auto &T : MI.tokens()) {

    if (T.hasLeadingSpace())

      OS << ' ';

    OS << PP.getSpelling(T, SpellingBuffer);

  }

}

//===----------------------------------------------------------------------===//

// Preprocessed token printer

//===----------------------------------------------------------------------===//

namespace {

class PrintPPOutputPPCallbacks : public PPCallbacks {

  Preprocessor &PP;

  SourceManager &SM;

  TokenConcatenation ConcatInfo;

public:

  raw_ostream &OS;

private:

  unsigned CurLine;

  bool EmittedTokensOnThisLine;

  bool EmittedDirectiveOnThisLine;

  SrcMgr::CharacteristicKind FileType;

  SmallString<512> CurFilename;

  bool Initialized;

  bool DisableLineMarkers;

  bool DumpDefines;

  bool DumpIncludeDirectives;

  bool UseLineDirectives;

  bool IsFirstFileEntered;

public:

  PrintPPOutputPPCallbacks(Preprocessor &pp, raw_ostream &os, bool lineMarkers,

                           bool defines, bool DumpIncludeDirectives,

                           bool UseLineDirectives)

      : PP(pp), SM(PP.getSourceManager()), ConcatInfo(PP), OS(os),

        DisableLineMarkers(lineMarkers), DumpDefines(defines),

        DumpIncludeDirectives(DumpIncludeDirectives),

        UseLineDirectives(UseLineDirectives) {

    CurLine = 0;

    CurFilename += "<uninit>";

    EmittedTokensOnThisLine = false;

    EmittedDirectiveOnThisLine = false;

    FileType = SrcMgr::C_User;

    Initialized = false;

    IsFirstFileEntered = false;

  }

  void setEmittedTokensOnThisLine() { EmittedTokensOnThisLine = true; }

  bool hasEmittedTokensOnThisLine() const { return EmittedTokensOnThisLine; }

  void setEmittedDirectiveOnThisLine() { EmittedDirectiveOnThisLine = true; }

  bool hasEmittedDirectiveOnThisLine() const {

    return EmittedDirectiveOnThisLine;

  }

  bool startNewLineIfNeeded(bool ShouldUpdateCurrentLine = true);

  void FileChanged(SourceLocation Loc, FileChangeReason Reason,

                   SrcMgr::CharacteristicKind FileType,

                   FileID PrevFID) override;

  void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,

                          StringRef FileName, bool IsAngled,

                          CharSourceRange FilenameRange, const FileEntry *File,

                          StringRef SearchPath, StringRef RelativePath,

                          const Module *Imported,

                          SrcMgr::CharacteristicKind FileType) override;

  void Ident(SourceLocation Loc, StringRef str) override;

  void PragmaMessage(SourceLocation Loc, StringRef Namespace,

                     PragmaMessageKind Kind, StringRef Str) override;

  void PragmaDebug(SourceLocation Loc, StringRef DebugType) override;

  void PragmaDiagnosticPush(SourceLocation Loc, StringRef Namespace) override;

  void PragmaDiagnosticPop(SourceLocation Loc, StringRef Namespace) override;

  void PragmaDiagnostic(SourceLocation Loc, StringRef Namespace,

                        diag::Severity Map, StringRef Str) override;

  void PragmaWarning(SourceLocation Loc, StringRef WarningSpec,

                     ArrayRef<int> Ids) override;

  void PragmaWarningPush(SourceLocation Loc, int Level) override;

  void PragmaWarningPop(SourceLocation Loc) override;

  void PragmaExecCharsetPush(SourceLocation Loc, StringRef Str) override;

  void PragmaExecCharsetPop(SourceLocation Loc) override;

  void PragmaAssumeNonNullBegin(SourceLocation Loc) override;

  void PragmaAssumeNonNullEnd(SourceLocation Loc) override;

  bool HandleFirstTokOnLine(Token &Tok);

  /// Move to the line of the provided source location. This will

  /// return true if the output stream required adjustment or if

  /// the requested location is on the first line.

  bool MoveToLine(SourceLocation Loc) {

    PresumedLoc PLoc = SM.getPresumedLoc(Loc);

    if (PLoc.isInvalid())

      return false;

    return MoveToLine(PLoc.getLine()) || 
(PLoc.getLine() == 1)581
;

  }

  bool MoveToLine(unsigned LineNo);

  bool AvoidConcat(const Token &PrevPrevTok, const Token &PrevTok,

                   const Token &Tok) {

    return ConcatInfo.AvoidConcat(PrevPrevTok, PrevTok, Tok);

  }

  void WriteLineInfo(unsigned LineNo, const char *Extra=nullptr,

                     unsigned ExtraLen=0);

  bool LineMarkersAreDisabled() const { return DisableLineMarkers; }

  void HandleNewlinesInToken(const char *TokStr, unsigned Len);

  /// MacroDefined - This hook is called whenever a macro definition is seen.

  void MacroDefined(const Token &MacroNameTok,

                    const MacroDirective *MD) override;

  /// MacroUndefined - This hook is called whenever a macro #undef is seen.

  void MacroUndefined(const Token &MacroNameTok,

                      const MacroDefinition &MD,

                      const MacroDirective *Undef) override;

  void BeginModule(const Module *M);

  void EndModule(const Module *M);

};

}  // end anonymous namespace

void PrintPPOutputPPCallbacks::WriteLineInfo(unsigned LineNo,

                                             const char *Extra,

                                             unsigned ExtraLen) {

  startNewLineIfNeeded(/*ShouldUpdateCurrentLine=*/false);

  // Emit #line directives or GNU line markers depending on what mode we're in.

  if (UseLineDirectives) {

    OS << "#line" << ' ' << LineNo << ' ' << '"';

    OS.write_escaped(CurFilename);

    OS << '"';

  } else {

    OS << '#' << ' ' << LineNo << ' ' << '"';

    OS.write_escaped(CurFilename);

    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(unsigned LineNo) {

  // 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 expansion line didn't.

    else {

      const char *NewLines = "\n\n\n\n\n\n\n\n";

      OS.write(NewLines, LineNo-CurLine);

    }

  } else if (!DisableLineMarkers) {

    // Emit a #line or line marker.

    WriteLineInfo(LineNo, nullptr, 0);

  } else {

    // Okay, we're in -P mode, which turns off line markers.  However, we still

    // need to emit a newline between tokens on different lines.

    startNewLineIfNeeded(/*ShouldUpdateCurrentLine=*/false);

  }

  CurLine = LineNo;

  return true;

}

bool

PrintPPOutputPPCallbacks::startNewLineIfNeeded(bool ShouldUpdateCurrentLine) {

  if (EmittedTokensOnThisLine || 
EmittedDirectiveOnThisLine4.78k
) {

    OS << '\n';

    EmittedTokensOnThisLine = false;

    EmittedDirectiveOnThisLine = false;

    if (ShouldUpdateCurrentLine)

      ++CurLine;

    return true;

  }

  return false;

}

/// 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,

                                       FileID PrevFID) {

  // Unless we are exiting a #include, make sure to skip ahead to the line the

  // #include directive was at.

  SourceManager &SourceMgr = SM;

  PresumedLoc UserLoc = SourceMgr.getPresumedLoc(Loc);

  if (UserLoc.isInvalid())

    return;

  unsigned NewLine = UserLoc.getLine();

  if (Reason == PPCallbacks::EnterFile) {

    SourceLocation IncludeLoc = UserLoc.getIncludeLoc();

    if (IncludeLoc.isValid())

      MoveToLine(IncludeLoc);

  } else if (Reason == PPCallbacks::SystemHeaderPragma) {

    // GCC emits the # directive for this directive on the line AFTER the

    // directive and emits a bunch of spaces that aren't needed. This is because

    // otherwise we will emit a line marker for THIS line, which requires an

    // extra blank line after the directive to avoid making all following lines

    // off by one. We can do better by simply incrementing NewLine here.

    NewLine += 1;

  }

  CurLine = NewLine;

  CurFilename.clear();

  CurFilename += UserLoc.getFilename();

  FileType = NewFileType;

  if (DisableLineMarkers) {

    startNewLineIfNeeded(/*ShouldUpdateCurrentLine=*/false);

    return;

  }

  if (!Initialized) {

    WriteLineInfo(CurLine);

    Initialized = true;

  }

  // Do not emit an enter marker for the main file (which we expect is the first

  // entered file). This matches gcc, and improves compatibility with some tools

  // which track the # line markers as a way to determine when the preprocessed

  // output is in the context of the main file.

  if (Reason == PPCallbacks::EnterFile && 
!IsFirstFileEntered1.87k
) {

    IsFirstFileEntered = true;

    return;

  }

  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;

  }

}

void PrintPPOutputPPCallbacks::InclusionDirective(

    SourceLocation HashLoc,

    const Token &IncludeTok,

    StringRef FileName,

    bool IsAngled,

    CharSourceRange FilenameRange,

    const FileEntry *File,

    StringRef SearchPath,

    StringRef RelativePath,

    const Module *Imported,

    SrcMgr::CharacteristicKind FileType) {

  // In -dI mode, dump #include directives prior to dumping their content or

  // interpretation.

  if (DumpIncludeDirectives) {

    startNewLineIfNeeded();

    MoveToLine(HashLoc);

    const std::string TokenText = PP.getSpelling(IncludeTok);

    assert(!TokenText.empty());

    OS << "#" << TokenText << " "

       << (IsAngled ? 
'<'1
 : '"') << FileName << (IsAngled ? 
'>'1
 : '"')

       << " /* clang -E -dI */";

    setEmittedDirectiveOnThisLine();

    startNewLineIfNeeded();

  }

  // When preprocessing, turn implicit imports into module import pragmas.

  if (Imported) {

    switch (IncludeTok.getIdentifierInfo()->getPPKeywordID()) {

    case tok::pp_include:

    case tok::pp_import:

    case tok::pp_include_next:

      startNewLineIfNeeded();

      MoveToLine(HashLoc);

      OS << "#pragma clang module import " << Imported->getFullModuleName(true)

         << " /* clang -E: implicit import for "

         << "#" << PP.getSpelling(IncludeTok) << " "

         << (IsAngled ? 
'<'8
 : '"') << FileName << (IsAngled ? 
'>'8
 : '"')

         << " */";

      // Since we want a newline after the pragma, but not a #<line>, start a

      // new line immediately.

      EmittedTokensOnThisLine = true;

      startNewLineIfNeeded();

      break;

    case tok::pp___include_macros:

      // #__include_macros has no effect on a user of a preprocessed source

      // file; the only effect is on preprocessing.

      //

      // FIXME: That's not *quite* true: it causes the module in question to

      // be loaded, which can affect downstream diagnostics.

      break;

    default:

      llvm_unreachable("unknown include directive kind");

      break;

    }

  }

}

/// Handle entering the scope of a module during a module compilation.

void PrintPPOutputPPCallbacks::BeginModule(const Module *M) {

  startNewLineIfNeeded();

  OS << "#pragma clang module begin " << M->getFullModuleName(true);

  setEmittedDirectiveOnThisLine();

}

/// Handle leaving the scope of a module during a module compilation.

void PrintPPOutputPPCallbacks::EndModule(const Module *M) {

  startNewLineIfNeeded();

  OS << "#pragma clang module end /*" << M->getFullModuleName(true) << "*/";

  setEmittedDirectiveOnThisLine();

}

/// Ident - Handle #ident directives when read by the preprocessor.

///

void PrintPPOutputPPCallbacks::Ident(SourceLocation Loc, StringRef S) {

  MoveToLine(Loc);

  OS.write("#ident ", strlen("#ident "));

  OS.write(S.begin(), S.size());

  EmittedTokensOnThisLine = true;

}

/// MacroDefined - This hook is called whenever a macro definition is seen.

void PrintPPOutputPPCallbacks::MacroDefined(const Token &MacroNameTok,

                                            const MacroDirective *MD) {

  const MacroInfo *MI = MD->getMacroInfo();

  // Only print out macro definitions in -dD mode.

  if (!DumpDefines ||

      // Ignore __FILE__ etc.

      
MI->isBuiltinMacro()995
) return;

  MoveToLine(MI->getDefinitionLoc());

  PrintMacroDefinition(*MacroNameTok.getIdentifierInfo(), *MI, PP, OS);

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::MacroUndefined(const Token &MacroNameTok,

                                              const MacroDefinition &MD,

                                              const MacroDirective *Undef) {

  // Only print out macro definitions in -dD mode.

  if (!DumpDefines) 
return209
;

  MoveToLine(MacroNameTok.getLocation());

  OS << "#undef " << MacroNameTok.getIdentifierInfo()->getName();

  setEmittedDirectiveOnThisLine();

}

static void outputPrintable(raw_ostream &OS, StringRef Str) {

  for (unsigned char Char : Str) {

    if (isPrintable(Char) && 
Char != '\\'41
 && 
Char != '"'39
)

      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));

  }

}

void PrintPPOutputPPCallbacks::PragmaMessage(SourceLocation Loc,

                                             StringRef Namespace,

                                             PragmaMessageKind Kind,

                                             StringRef Str) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma ";

  if (!Namespace.empty())

    OS << Namespace << ' ';

  switch (Kind) {

    case PMK_Message:

      OS << "message(\"";

      break;

    case PMK_Warning:

      OS << "warning \"";

      break;

    case PMK_Error:

      OS << "error \"";

      break;

  }

  outputPrintable(OS, Str);

  OS << '"';

  if (Kind == PMK_Message)

    OS << ')';

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::PragmaDebug(SourceLocation Loc,

                                           StringRef DebugType) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma clang __debug ";

  OS << DebugType;

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::

PragmaDiagnosticPush(SourceLocation Loc, StringRef Namespace) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma " << Namespace << " diagnostic push";

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::

PragmaDiagnosticPop(SourceLocation Loc, StringRef Namespace) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma " << Namespace << " diagnostic pop";

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::PragmaDiagnostic(SourceLocation Loc,

                                                StringRef Namespace,

                                                diag::Severity Map,

                                                StringRef Str) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma " << Namespace << " diagnostic ";

  switch (Map) {

  case diag::Severity::Remark:

    OS << "remark";

    break;

  case diag::Severity::Warning:

    OS << "warning";

    break;

  case diag::Severity::Error:

    OS << "error";

    break;

  case diag::Severity::Ignored:

    OS << "ignored";

    break;

  case diag::Severity::Fatal:

    OS << "fatal";

    break;

  }

  OS << " \"" << Str << '"';

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::PragmaWarning(SourceLocation Loc,

                                             StringRef WarningSpec,

                                             ArrayRef<int> Ids) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma warning(" << WarningSpec << ':';

  for (ArrayRef<int>::iterator I = Ids.begin(), E = Ids.end(); I != E; 
++I24
)

    OS << ' ' << *I;

  OS << ')';

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::PragmaWarningPush(SourceLocation Loc,

                                                 int Level) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma warning(push";

  if (Level >= 0)

    OS << ", " << Level;

  OS << ')';

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::PragmaWarningPop(SourceLocation Loc) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma warning(pop)";

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::PragmaExecCharsetPush(SourceLocation Loc,

                                                     StringRef Str) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma character_execution_set(push";

  if (!Str.empty())

    OS << ", " << Str;

  OS << ')';

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::PragmaExecCharsetPop(SourceLocation Loc) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma character_execution_set(pop)";

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::

PragmaAssumeNonNullBegin(SourceLocation Loc) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma clang assume_nonnull begin";

  setEmittedDirectiveOnThisLine();

}

void PrintPPOutputPPCallbacks::

PragmaAssumeNonNullEnd(SourceLocation Loc) {

  startNewLineIfNeeded();

  MoveToLine(Loc);

  OS << "#pragma clang assume_nonnull end";

  setEmittedDirectiveOnThisLine();

}

/// 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 expansion 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.

  unsigned ColNo = SM.getExpansionColumnNumber(Tok.getLocation());

  // The first token on a line can have a column number of 1, yet still expect

  // leading white space, if a macro expansion in column 1 starts with an empty

  // macro argument, or an empty nested macro expansion. In this case, move the

  // token to column 2.

  if (ColNo == 1 && 
Tok.hasLeadingSpace()33.6k
)

    ColNo = 2;

  // 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)33.6k
)

    OS << ' ';

  // Otherwise, indent the appropriate number of spaces.

  for (; ColNo > 1; 
--ColNo179k
)

    OS << ' ';

  return true;

}

void PrintPPOutputPPCallbacks::HandleNewlinesInToken(const char *TokStr,

                                                     unsigned Len) {

  unsigned NumNewlines = 0;

  for (; Len; 
--Len, ++TokStr660k
) {

    if (*TokStr != '\n' &&

        *TokStr != '\r')

      continue;

    ++NumNewlines;

    // If we have \n\r or \r\n, skip both and count as one line.

    if (Len != 1 &&

        (TokStr[1] == '\n' || 
TokStr[1] == '\r'937
) &&

        TokStr[0] != TokStr[1]) {

      ++TokStr;

      --Len;

    }

  }

  if (NumNewlines == 0) 
return15.0k
;

  CurLine += NumNewlines;

}

namespace {

struct UnknownPragmaHandler : public PragmaHandler {

  const char *Prefix;

  PrintPPOutputPPCallbacks *Callbacks;

  // Set to true if tokens should be expanded

  bool ShouldExpandTokens;

  UnknownPragmaHandler(const char *prefix, PrintPPOutputPPCallbacks *callbacks,

                       bool RequireTokenExpansion)

      : Prefix(prefix), Callbacks(callbacks),

        ShouldExpandTokens(RequireTokenExpansion) {}

  void HandlePragma(Preprocessor &PP, PragmaIntroducer Introducer,

                    Token &PragmaTok) override {

    // Figure out what line we went to and insert the appropriate number of

    // newline characters.

    Callbacks->startNewLineIfNeeded();

    Callbacks->MoveToLine(PragmaTok.getLocation());

    Callbacks->OS.write(Prefix, strlen(Prefix));

    if (ShouldExpandTokens) {

      // The first token does not have expanded macros. Expand them, if

      // required.

      auto Toks = std::make_unique<Token[]>(1);

      Toks[0] = PragmaTok;

      PP.EnterTokenStream(std::move(Toks), /*NumToks=*/1,

                          /*DisableMacroExpansion=*/false,

                          /*IsReinject=*/false);

      PP.Lex(PragmaTok);

    }

    Token PrevToken;

    Token PrevPrevToken;

    PrevToken.startToken();

    PrevPrevToken.startToken();

    // Read and print all of the pragma tokens.

    while (PragmaTok.isNot(tok::eod)) {

      if (PragmaTok.hasLeadingSpace() ||

          Callbacks->AvoidConcat(PrevPrevToken, PrevToken, PragmaTok))

        Callbacks->OS << ' ';

      std::string TokSpell = PP.getSpelling(PragmaTok);

      Callbacks->OS.write(&TokSpell[0], TokSpell.size());

      PrevPrevToken = PrevToken;

      PrevToken = PragmaTok;

      if (ShouldExpandTokens)

        PP.Lex(PragmaTok);

      else

        PP.LexUnexpandedToken(PragmaTok);

    }

    Callbacks->setEmittedDirectiveOnThisLine();

  }

};

} // end anonymous namespace

static void PrintPreprocessedTokens(Preprocessor &PP, Token &Tok,

                                    PrintPPOutputPPCallbacks *Callbacks,

                                    raw_ostream &OS) {

  bool DropComments = PP.getLangOpts().TraditionalCPP &&

                      !PP.getCommentRetentionState();

  char Buffer[256];

  Token PrevPrevTok, PrevTok;

  PrevPrevTok.startToken();

  PrevTok.startToken();

  while (1) {

    if (Callbacks->hasEmittedDirectiveOnThisLine()) {

      Callbacks->startNewLineIfNeeded();

      Callbacks->MoveToLine(Tok.getLocation());

    }

    // If this token is at the start of a line, emit newlines if needed.

    if (Tok.isAtStartOfLine() && 
Callbacks->HandleFirstTokOnLine(Tok)44.4k
) {

      // 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(PrevPrevTok, PrevTok, Tok))) {

      OS << ' ';

    }

    if (DropComments && 
Tok.is(tok::comment)275
) {

      // Skip comments. Normally the preprocessor does not generate

      // tok::comment nodes at all when not keeping comments, but under

      // -traditional-cpp the lexer keeps /all/ whitespace, including comments.

      SourceLocation StartLoc = Tok.getLocation();

      Callbacks->MoveToLine(StartLoc.getLocWithOffset(Tok.getLength()));

    } else if (Tok.is(tok::eod)) {

      // Don't print end of directive tokens, since they are typically newlines

      // that mess up our line tracking. These come from unknown pre-processor

      // directives or hash-prefixed comments in standalone assembly files.

      PP.Lex(Tok);

      continue;

    } else if (Tok.is(tok::annot_module_include)) {

      // PrintPPOutputPPCallbacks::InclusionDirective handles producing

      // appropriate output here. Ignore this token entirely.

      PP.Lex(Tok);

      continue;

    } else if (Tok.is(tok::annot_module_begin)) {

      // FIXME: We retrieve this token after the FileChanged callback, and

      // retrieve the module_end token before the FileChanged callback, so

      // we render this within the file and render the module end outside the

      // file, but this is backwards from the token locations: the module_begin

      // token is at the include location (outside the file) and the module_end

      // token is at the EOF location (within the file).

      Callbacks->BeginModule(

          reinterpret_cast<Module *>(Tok.getAnnotationValue()));

      PP.Lex(Tok);

      continue;

    } else if (Tok.is(tok::annot_module_end)) {

      Callbacks->EndModule(

          reinterpret_cast<Module *>(Tok.getAnnotationValue()));

      PP.Lex(Tok);

      continue;

    } else if (Tok.is(tok::annot_header_unit)) {

      // This is a header-name that has been (effectively) converted into a

      // module-name.

      // FIXME: The module name could contain non-identifier module name

      // components. We don't have a good way to round-trip those.

      Module *M = reinterpret_cast<Module *>(Tok.getAnnotationValue());

      std::string Name = M->getFullModuleName();

      OS.write(Name.data(), Name.size());

      Callbacks->HandleNewlinesInToken(Name.data(), Name.size());

    } else if (Tok.isAnnotation()) {

      // Ignore annotation tokens created by pragmas - the pragmas themselves

      // will be reproduced in the preprocessed output.

      PP.Lex(Tok);

      continue;

    } else if (IdentifierInfo *II = Tok.getIdentifierInfo()) {

      OS << II->getName();

    } else if (Tok.isLiteral() && 
!Tok.needsCleaning()14.1k
 &&

               Tok.getLiteralData()) {

      OS.write(Tok.getLiteralData(), Tok.getLength());

    } else if (Tok.getLength() < llvm::array_lengthof(Buffer)) {

      const char *TokPtr = Buffer;

      unsigned Len = PP.getSpelling(Tok, TokPtr);

      OS.write(TokPtr, Len);

      // Tokens that can contain embedded newlines need to adjust our current

      // line number.

      if (Tok.getKind() == tok::comment || 
Tok.getKind() == tok::unknown440k
)

        Callbacks->HandleNewlinesInToken(TokPtr, Len);

    } else {

      std::string S = PP.getSpelling(Tok);

      OS.write(S.data(), S.size());

      // Tokens that can contain embedded newlines need to adjust our current

      // line number.

      if (Tok.getKind() == tok::comment || 
Tok.getKind() == tok::unknown0
)

        Callbacks->HandleNewlinesInToken(S.data(), S.size());

    }

    Callbacks->setEmittedTokensOnThisLine();

    if (Tok.is(tok::eof)) 
break505
;

    PrevPrevTok = PrevTok;

    PrevTok = Tok;

    PP.Lex(Tok);

  }

}

typedef std::pair<const IdentifierInfo *, MacroInfo *> id_macro_pair;

static int MacroIDCompare(const id_macro_pair *LHS, const id_macro_pair *RHS) {

  return LHS->first->getName().compare(RHS->first->getName());

}

static void DoPrintMacros(Preprocessor &PP, raw_ostream *OS) {

  // Ignore unknown pragmas.

  PP.IgnorePragmas();

  // -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));

  SmallVector<id_macro_pair, 128> MacrosByID;

  for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();

       I != E; 
++I500k
) {

    auto *MD = I->second.getLatest();

    if (MD && MD->isDefined())

      MacrosByID.push_back(id_macro_pair(I->first, MD->getMacroInfo()));

  }

  llvm::array_pod_sort(MacrosByID.begin(), MacrosByID.end(), MacroIDCompare);

  for (unsigned i = 0, e = MacrosByID.size(); i != e; 
++i500k
) {

    MacroInfo &MI = *MacrosByID[i].second;

    // Ignore computed macros like __LINE__ and friends.

    if (MI.isBuiltinMacro()) 
continue34.2k
;

    PrintMacroDefinition(*MacrosByID[i].first, MI, PP, *OS);

    *OS << '\n';

  }

}

/// DoPrintPreprocessedInput - This implements -E mode.

///

void clang::DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,

                                     const PreprocessorOutputOptions &Opts) {

  // Show macros with no output is handled specially.

  if (!Opts.ShowCPP) {

    assert(Opts.ShowMacros && "Not yet implemented!");

    DoPrintMacros(PP, OS);

    return;

  }

  // Inform the preprocessor whether we want it to retain comments or not, due

  // to -C or -CC.

  PP.SetCommentRetentionState(Opts.ShowComments, Opts.ShowMacroComments);

  PrintPPOutputPPCallbacks *Callbacks = new PrintPPOutputPPCallbacks(

      PP, *OS, !Opts.ShowLineMarkers, Opts.ShowMacros,

      Opts.ShowIncludeDirectives, Opts.UseLineDirectives);

  // Expand macros in pragmas with -fms-extensions.  The assumption is that

  // the majority of pragmas in such a file will be Microsoft pragmas.

  // Remember the handlers we will add so that we can remove them later.

  std::unique_ptr<UnknownPragmaHandler> MicrosoftExtHandler(

      new UnknownPragmaHandler(

          "#pragma", Callbacks,

          /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));

  std::unique_ptr<UnknownPragmaHandler> GCCHandler(new UnknownPragmaHandler(

      "#pragma GCC", Callbacks,

      /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));

  std::unique_ptr<UnknownPragmaHandler> ClangHandler(new UnknownPragmaHandler(

      "#pragma clang", Callbacks,

      /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));

  PP.AddPragmaHandler(MicrosoftExtHandler.get());

  PP.AddPragmaHandler("GCC", GCCHandler.get());

  PP.AddPragmaHandler("clang", ClangHandler.get());

  // The tokens after pragma omp need to be expanded.

  //

  //  OpenMP [2.1, Directive format]

  //  Preprocessing tokens following the #pragma omp are subject to macro

  //  replacement.

  std::unique_ptr<UnknownPragmaHandler> OpenMPHandler(

      new UnknownPragmaHandler("#pragma omp", Callbacks,

                               /*RequireTokenExpansion=*/true));

  PP.AddPragmaHandler("omp", OpenMPHandler.get());

  PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(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);

    if (Tok.is(tok::eof) || 
!Tok.getLocation().isFileID()413
)

      break;

    PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());

    if (PLoc.isInvalid())

      break;

    if (strcmp(PLoc.getFilename(), "<built-in>"))

      break;

  } while (true);

  // Read all the preprocessed tokens, printing them out to the stream.

  PrintPreprocessedTokens(PP, Tok, Callbacks, *OS);

  *OS << '\n';

  // Remove the handlers we just added to leave the preprocessor in a sane state

  // so that it can be reused (for example by a clang::Parser instance).

  PP.RemovePragmaHandler(MicrosoftExtHandler.get());

  PP.RemovePragmaHandler("GCC", GCCHandler.get());

  PP.RemovePragmaHandler("clang", ClangHandler.get());

  PP.RemovePragmaHandler("omp", OpenMPHandler.get());

}