clang/lib/Frontend/PrintPreprocessedOutput.cpp

   1 //===--- PrintPreprocessedOutput.cpp - Implement the -E mode --------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This code simply runs the preprocessor on the input file and prints out the
  10 // result.  This is the traditional behavior of the -E option.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "clang/Frontend/Utils.h"
  15 #include "clang/Basic/CharInfo.h"
  16 #include "clang/Basic/Diagnostic.h"
  17 #include "clang/Basic/SourceManager.h"
  18 #include "clang/Frontend/PreprocessorOutputOptions.h"
  19 #include "clang/Lex/MacroInfo.h"
  20 #include "clang/Lex/PPCallbacks.h"
  21 #include "clang/Lex/Pragma.h"
  22 #include "clang/Lex/Preprocessor.h"
  23 #include "clang/Lex/TokenConcatenation.h"
  24 #include "llvm/ADT/STLExtras.h"
  25 #include "llvm/ADT/SmallString.h"
  26 #include "llvm/ADT/StringRef.h"
  27 #include "llvm/Support/ErrorHandling.h"
  28 #include "llvm/Support/raw_ostream.h"
  29 #include <cstdio>
  30 using namespace clang;
  31
  32 /// PrintMacroDefinition - Print a macro definition in a form that will be
  33 /// properly accepted back as a definition.
  34 static void PrintMacroDefinition(const IdentifierInfo &II, const MacroInfo &MI,
  35                                  Preprocessor &PP, raw_ostream *OS) {
  36   *OS << "#define " << II.getName();
  37
  38   if (MI.isFunctionLike()) {
  39     *OS << '(';
  40     if (!MI.param_empty()) {
  41       MacroInfo::param_iterator AI = MI.param_begin(), E = MI.param_end();
  42       for (; AI+1 != E; ++AI) {
  43         *OS << (*AI)->getName();
  44         *OS << ',';
  45       }
  46
  47       // Last argument.
  48       if ((*AI)->getName() == "__VA_ARGS__")
  49         *OS << "...";
  50       else
  51         *OS << (*AI)->getName();
  52     }
  53
  54     if (MI.isGNUVarargs())
  55       *OS << "...";  // #define foo(x...)
  56
  57     *OS << ')';
  58   }
  59
  60   // GCC always emits a space, even if the macro body is empty.  However, do not
  61   // want to emit two spaces if the first token has a leading space.
  62   if (MI.tokens_empty() || !MI.tokens_begin()->hasLeadingSpace())
  63     *OS << ' ';
  64
  65   SmallString<128> SpellingBuffer;
  66   for (const auto &T : MI.tokens()) {
  67     if (T.hasLeadingSpace())
  68       *OS << ' ';
  69
  70     *OS << PP.getSpelling(T, SpellingBuffer);
  71   }
  72 }
  73
  74 //===----------------------------------------------------------------------===//
  75 // Preprocessed token printer
  76 //===----------------------------------------------------------------------===//
  77
  78 namespace {
  79 class PrintPPOutputPPCallbacks : public PPCallbacks {
  80   Preprocessor &PP;
  81   SourceManager &SM;
  82   TokenConcatenation ConcatInfo;
  83 public:
  84   raw_ostream *OS;
  85 private:
  86   unsigned CurLine;
  87
  88   bool EmittedTokensOnThisLine;
  89   bool EmittedDirectiveOnThisLine;
  90   SrcMgr::CharacteristicKind FileType;
  91   SmallString<512> CurFilename;
  92   bool Initialized;
  93   bool DisableLineMarkers;
  94   bool DumpDefines;
  95   bool DumpIncludeDirectives;
  96   bool UseLineDirectives;
  97   bool IsFirstFileEntered;
  98   bool MinimizeWhitespace;
  99   bool DirectivesOnly;
 100   bool KeepSystemIncludes;
 101   raw_ostream *OrigOS;
 102   std::unique_ptr<llvm::raw_null_ostream> NullOS;
 103
 104   Token PrevTok;
 105   Token PrevPrevTok;
 106
 107 public:
 108   PrintPPOutputPPCallbacks(Preprocessor &pp, raw_ostream *os, bool lineMarkers,
 109                            bool defines, bool DumpIncludeDirectives,
 110                            bool UseLineDirectives, bool MinimizeWhitespace,
 111                            bool DirectivesOnly, bool KeepSystemIncludes)
 112       : PP(pp), SM(PP.getSourceManager()), ConcatInfo(PP), OS(os),
 113         DisableLineMarkers(lineMarkers), DumpDefines(defines),
 114         DumpIncludeDirectives(DumpIncludeDirectives),
 115         UseLineDirectives(UseLineDirectives),
 116         MinimizeWhitespace(MinimizeWhitespace), DirectivesOnly(DirectivesOnly),
 117         KeepSystemIncludes(KeepSystemIncludes), OrigOS(os) {
 118     CurLine = 0;
 119     CurFilename += "<uninit>";
 120     EmittedTokensOnThisLine = false;
 121     EmittedDirectiveOnThisLine = false;
 122     FileType = SrcMgr::C_User;
 123     Initialized = false;
 124     IsFirstFileEntered = false;
 125     if (KeepSystemIncludes)
 126       NullOS = std::make_unique<llvm::raw_null_ostream>();
 127
 128     PrevTok.startToken();
 129     PrevPrevTok.startToken();
 130   }
 131
 132   bool isMinimizeWhitespace() const { return MinimizeWhitespace; }
 133
 134   void setEmittedTokensOnThisLine() { EmittedTokensOnThisLine = true; }
 135   bool hasEmittedTokensOnThisLine() const { return EmittedTokensOnThisLine; }
 136
 137   void setEmittedDirectiveOnThisLine() { EmittedDirectiveOnThisLine = true; }
 138   bool hasEmittedDirectiveOnThisLine() const {
 139     return EmittedDirectiveOnThisLine;
 140   }
 141
 142   /// Ensure that the output stream position is at the beginning of a new line
 143   /// and inserts one if it does not. It is intended to ensure that directives
 144   /// inserted by the directives not from the input source (such as #line) are
 145   /// in the first column. To insert newlines that represent the input, use
 146   /// MoveToLine(/*...*/, /*RequireStartOfLine=*/true).
 147   void startNewLineIfNeeded();
 148
 149   void FileChanged(SourceLocation Loc, FileChangeReason Reason,
 150                    SrcMgr::CharacteristicKind FileType,
 151                    FileID PrevFID) override;
 152   void InclusionDirective(SourceLocation HashLoc, const Token &IncludeTok,
 153                           StringRef FileName, bool IsAngled,
 154                           CharSourceRange FilenameRange,
 155                           OptionalFileEntryRef File, StringRef SearchPath,
 156                           StringRef RelativePath, const Module *Imported,
 157                           SrcMgr::CharacteristicKind FileType) override;
 158   void Ident(SourceLocation Loc, StringRef str) override;
 159   void PragmaMessage(SourceLocation Loc, StringRef Namespace,
 160                      PragmaMessageKind Kind, StringRef Str) override;
 161   void PragmaDebug(SourceLocation Loc, StringRef DebugType) override;
 162   void PragmaDiagnosticPush(SourceLocation Loc, StringRef Namespace) override;
 163   void PragmaDiagnosticPop(SourceLocation Loc, StringRef Namespace) override;
 164   void PragmaDiagnostic(SourceLocation Loc, StringRef Namespace,
 165                         diag::Severity Map, StringRef Str) override;
 166   void PragmaWarning(SourceLocation Loc, PragmaWarningSpecifier WarningSpec,
 167                      ArrayRef<int> Ids) override;
 168   void PragmaWarningPush(SourceLocation Loc, int Level) override;
 169   void PragmaWarningPop(SourceLocation Loc) override;
 170   void PragmaExecCharsetPush(SourceLocation Loc, StringRef Str) override;
 171   void PragmaExecCharsetPop(SourceLocation Loc) override;
 172   void PragmaAssumeNonNullBegin(SourceLocation Loc) override;
 173   void PragmaAssumeNonNullEnd(SourceLocation Loc) override;
 174
 175   /// Insert whitespace before emitting the next token.
 176   ///
 177   /// @param Tok             Next token to be emitted.
 178   /// @param RequireSpace    Ensure at least one whitespace is emitted. Useful
 179   ///                        if non-tokens have been emitted to the stream.
 180   /// @param RequireSameLine Never emit newlines. Useful when semantics depend
 181   ///                        on being on the same line, such as directives.
 182   void HandleWhitespaceBeforeTok(const Token &Tok, bool RequireSpace,
 183                                  bool RequireSameLine);
 184
 185   /// Move to the line of the provided source location. This will
 186   /// return true if a newline was inserted or if
 187   /// the requested location is the first token on the first line.
 188   /// In these cases the next output will be the first column on the line and
 189   /// make it possible to insert indention. The newline was inserted
 190   /// implicitly when at the beginning of the file.
 191   ///
 192   /// @param Tok                 Token where to move to.
 193   /// @param RequireStartOfLine  Whether the next line depends on being in the
 194   ///                            first column, such as a directive.
 195   ///
 196   /// @return Whether column adjustments are necessary.
 197   bool MoveToLine(const Token &Tok, bool RequireStartOfLine) {
 198     PresumedLoc PLoc = SM.getPresumedLoc(Tok.getLocation());
 199     unsigned TargetLine = PLoc.isValid() ? PLoc.getLine() : CurLine;
 200     bool IsFirstInFile =
 201         Tok.isAtStartOfLine() && PLoc.isValid() && PLoc.getLine() == 1;
 202     return MoveToLine(TargetLine, RequireStartOfLine) || IsFirstInFile;
 203   }
 204
 205   /// Move to the line of the provided source location. Returns true if a new
 206   /// line was inserted.
 207   bool MoveToLine(SourceLocation Loc, bool RequireStartOfLine) {
 208     PresumedLoc PLoc = SM.getPresumedLoc(Loc);
 209     unsigned TargetLine = PLoc.isValid() ? PLoc.getLine() : CurLine;
 210     return MoveToLine(TargetLine, RequireStartOfLine);
 211   }
 212   bool MoveToLine(unsigned LineNo, bool RequireStartOfLine);
 213
 214   bool AvoidConcat(const Token &PrevPrevTok, const Token &PrevTok,
 215                    const Token &Tok) {
 216     return ConcatInfo.AvoidConcat(PrevPrevTok, PrevTok, Tok);
 217   }
 218   void WriteLineInfo(unsigned LineNo, const char *Extra=nullptr,
 219                      unsigned ExtraLen=0);
 220   bool LineMarkersAreDisabled() const { return DisableLineMarkers; }
 221   void HandleNewlinesInToken(const char *TokStr, unsigned Len);
 222
 223   /// MacroDefined - This hook is called whenever a macro definition is seen.
 224   void MacroDefined(const Token &MacroNameTok,
 225                     const MacroDirective *MD) override;
 226
 227   /// MacroUndefined - This hook is called whenever a macro #undef is seen.
 228   void MacroUndefined(const Token &MacroNameTok,
 229                       const MacroDefinition &MD,
 230                       const MacroDirective *Undef) override;
 231
 232   void BeginModule(const Module *M);
 233   void EndModule(const Module *M);
 234 };
 235 }  // end anonymous namespace
 236
 237 void PrintPPOutputPPCallbacks::WriteLineInfo(unsigned LineNo,
 238                                              const char *Extra,
 239                                              unsigned ExtraLen) {
 240   startNewLineIfNeeded();
 241
 242   // Emit #line directives or GNU line markers depending on what mode we're in.
 243   if (UseLineDirectives) {
 244     *OS << "#line" << ' ' << LineNo << ' ' << '"';
 245     OS->write_escaped(CurFilename);
 246     *OS << '"';
 247   } else {
 248     *OS << '#' << ' ' << LineNo << ' ' << '"';
 249     OS->write_escaped(CurFilename);
 250     *OS << '"';
 251
 252     if (ExtraLen)
 253       OS->write(Extra, ExtraLen);
 254
 255     if (FileType == SrcMgr::C_System)
 256       OS->write(" 3", 2);
 257     else if (FileType == SrcMgr::C_ExternCSystem)
 258       OS->write(" 3 4", 4);
 259   }
 260   *OS << '\n';
 261 }
 262
 263 /// MoveToLine - Move the output to the source line specified by the location
 264 /// object.  We can do this by emitting some number of \n's, or be emitting a
 265 /// #line directive.  This returns false if already at the specified line, true
 266 /// if some newlines were emitted.
 267 bool PrintPPOutputPPCallbacks::MoveToLine(unsigned LineNo,
 268                                           bool RequireStartOfLine) {
 269   // If it is required to start a new line or finish the current, insert
 270   // vertical whitespace now and take it into account when moving to the
 271   // expected line.
 272   bool StartedNewLine = false;
 273   if ((RequireStartOfLine && EmittedTokensOnThisLine) ||
 274       EmittedDirectiveOnThisLine) {
 275     *OS << '\n';
 276     StartedNewLine = true;
 277     CurLine += 1;
 278     EmittedTokensOnThisLine = false;
 279     EmittedDirectiveOnThisLine = false;
 280   }
 281
 282   // If this line is "close enough" to the original line, just print newlines,
 283   // otherwise print a #line directive.
 284   if (CurLine == LineNo) {
 285     // Nothing to do if we are already on the correct line.
 286   } else if (MinimizeWhitespace && DisableLineMarkers) {
 287     // With -E -P -fminimize-whitespace, don't emit anything if not necessary.
 288   } else if (!StartedNewLine && LineNo - CurLine == 1) {
 289     // Printing a single line has priority over printing a #line directive, even
 290     // when minimizing whitespace which otherwise would print #line directives
 291     // for every single line.
 292     *OS << '\n';
 293     StartedNewLine = true;
 294   } else if (!DisableLineMarkers) {
 295     if (LineNo - CurLine <= 8) {
 296       const char *NewLines = "\n\n\n\n\n\n\n\n";
 297       OS->write(NewLines, LineNo - CurLine);
 298     } else {
 299       // Emit a #line or line marker.
 300       WriteLineInfo(LineNo, nullptr, 0);
 301     }
 302     StartedNewLine = true;
 303   } else if (EmittedTokensOnThisLine) {
 304     // If we are not on the correct line and don't need to be line-correct,
 305     // at least ensure we start on a new line.
 306     *OS << '\n';
 307     StartedNewLine = true;
 308   }
 309
 310   if (StartedNewLine) {
 311     EmittedTokensOnThisLine = false;
 312     EmittedDirectiveOnThisLine = false;
 313   }
 314
 315   CurLine = LineNo;
 316   return StartedNewLine;
 317 }
 318
 319 void PrintPPOutputPPCallbacks::startNewLineIfNeeded() {
 320   if (EmittedTokensOnThisLine || EmittedDirectiveOnThisLine) {
 321     *OS << '\n';
 322     EmittedTokensOnThisLine = false;
 323     EmittedDirectiveOnThisLine = false;
 324   }
 325 }
 326
 327 /// FileChanged - Whenever the preprocessor enters or exits a #include file
 328 /// it invokes this handler.  Update our conception of the current source
 329 /// position.
 330 void PrintPPOutputPPCallbacks::FileChanged(SourceLocation Loc,
 331                                            FileChangeReason Reason,
 332                                        SrcMgr::CharacteristicKind NewFileType,
 333                                        FileID PrevFID) {
 334   // Unless we are exiting a #include, make sure to skip ahead to the line the
 335   // #include directive was at.
 336   SourceManager &SourceMgr = SM;
 337
 338   PresumedLoc UserLoc = SourceMgr.getPresumedLoc(Loc);
 339   if (UserLoc.isInvalid())
 340     return;
 341
 342   unsigned NewLine = UserLoc.getLine();
 343
 344   if (Reason == PPCallbacks::EnterFile) {
 345     SourceLocation IncludeLoc = UserLoc.getIncludeLoc();
 346     if (IncludeLoc.isValid())
 347       MoveToLine(IncludeLoc, /*RequireStartOfLine=*/false);
 348   } else if (Reason == PPCallbacks::SystemHeaderPragma) {
 349     // GCC emits the # directive for this directive on the line AFTER the
 350     // directive and emits a bunch of spaces that aren't needed. This is because
 351     // otherwise we will emit a line marker for THIS line, which requires an
 352     // extra blank line after the directive to avoid making all following lines
 353     // off by one. We can do better by simply incrementing NewLine here.
 354     NewLine += 1;
 355   }
 356
 357   CurLine = NewLine;
 358
 359   // In KeepSystemIncludes mode, redirect OS as needed.
 360   if (KeepSystemIncludes && (isSystem(FileType) != isSystem(NewFileType)))
 361     OS = isSystem(FileType) ? OrigOS : NullOS.get();
 362
 363   CurFilename.clear();
 364   CurFilename += UserLoc.getFilename();
 365   FileType = NewFileType;
 366
 367   if (DisableLineMarkers) {
 368     if (!MinimizeWhitespace)
 369       startNewLineIfNeeded();
 370     return;
 371   }
 372
 373   if (!Initialized) {
 374     WriteLineInfo(CurLine);
 375     Initialized = true;
 376   }
 377
 378   // Do not emit an enter marker for the main file (which we expect is the first
 379   // entered file). This matches gcc, and improves compatibility with some tools
 380   // which track the # line markers as a way to determine when the preprocessed
 381   // output is in the context of the main file.
 382   if (Reason == PPCallbacks::EnterFile && !IsFirstFileEntered) {
 383     IsFirstFileEntered = true;
 384     return;
 385   }
 386
 387   switch (Reason) {
 388   case PPCallbacks::EnterFile:
 389     WriteLineInfo(CurLine, " 1", 2);
 390     break;
 391   case PPCallbacks::ExitFile:
 392     WriteLineInfo(CurLine, " 2", 2);
 393     break;
 394   case PPCallbacks::SystemHeaderPragma:
 395   case PPCallbacks::RenameFile:
 396     WriteLineInfo(CurLine);
 397     break;
 398   }
 399 }
 400
 401 void PrintPPOutputPPCallbacks::InclusionDirective(
 402     SourceLocation HashLoc, const Token &IncludeTok, StringRef FileName,
 403     bool IsAngled, CharSourceRange FilenameRange, OptionalFileEntryRef File,
 404     StringRef SearchPath, StringRef RelativePath, const Module *Imported,
 405     SrcMgr::CharacteristicKind FileType) {
 406   // In -dI mode, dump #include directives prior to dumping their content or
 407   // interpretation. Similar for -fkeep-system-includes.
 408   if (DumpIncludeDirectives || (KeepSystemIncludes && isSystem(FileType))) {
 409     MoveToLine(HashLoc, /*RequireStartOfLine=*/true);
 410     const std::string TokenText = PP.getSpelling(IncludeTok);
 411     assert(!TokenText.empty());
 412     *OS << "#" << TokenText << " "
 413         << (IsAngled ? '<' : '"') << FileName << (IsAngled ? '>' : '"')
 414         << " /* clang -E "
 415         << (DumpIncludeDirectives ? "-dI" : "-fkeep-system-includes")
 416         << " */";
 417     setEmittedDirectiveOnThisLine();
 418   }
 419
 420   // When preprocessing, turn implicit imports into module import pragmas.
 421   if (Imported) {
 422     switch (IncludeTok.getIdentifierInfo()->getPPKeywordID()) {
 423     case tok::pp_include:
 424     case tok::pp_import:
 425     case tok::pp_include_next:
 426       MoveToLine(HashLoc, /*RequireStartOfLine=*/true);
 427       *OS << "#pragma clang module import "
 428           << Imported->getFullModuleName(true)
 429           << " /* clang -E: implicit import for "
 430           << "#" << PP.getSpelling(IncludeTok) << " "
 431           << (IsAngled ? '<' : '"') << FileName << (IsAngled ? '>' : '"')
 432           << " */";
 433       setEmittedDirectiveOnThisLine();
 434       break;
 435
 436     case tok::pp___include_macros:
 437       // #__include_macros has no effect on a user of a preprocessed source
 438       // file; the only effect is on preprocessing.
 439       //
 440       // FIXME: That's not *quite* true: it causes the module in question to
 441       // be loaded, which can affect downstream diagnostics.
 442       break;
 443
 444     default:
 445       llvm_unreachable("unknown include directive kind");
 446       break;
 447     }
 448   }
 449 }
 450
 451 /// Handle entering the scope of a module during a module compilation.
 452 void PrintPPOutputPPCallbacks::BeginModule(const Module *M) {
 453   startNewLineIfNeeded();
 454   *OS << "#pragma clang module begin " << M->getFullModuleName(true);
 455   setEmittedDirectiveOnThisLine();
 456 }
 457
 458 /// Handle leaving the scope of a module during a module compilation.
 459 void PrintPPOutputPPCallbacks::EndModule(const Module *M) {
 460   startNewLineIfNeeded();
 461   *OS << "#pragma clang module end /*" << M->getFullModuleName(true) << "*/";
 462   setEmittedDirectiveOnThisLine();
 463 }
 464
 465 /// Ident - Handle #ident directives when read by the preprocessor.
 466 ///
 467 void PrintPPOutputPPCallbacks::Ident(SourceLocation Loc, StringRef S) {
 468   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 469
 470   OS->write("#ident ", strlen("#ident "));
 471   OS->write(S.begin(), S.size());
 472   setEmittedTokensOnThisLine();
 473 }
 474
 475 /// MacroDefined - This hook is called whenever a macro definition is seen.
 476 void PrintPPOutputPPCallbacks::MacroDefined(const Token &MacroNameTok,
 477                                             const MacroDirective *MD) {
 478   const MacroInfo *MI = MD->getMacroInfo();
 479   // Print out macro definitions in -dD mode and when we have -fdirectives-only
 480   // for C++20 header units.
 481   if ((!DumpDefines && !DirectivesOnly) ||
 482       // Ignore __FILE__ etc.
 483       MI->isBuiltinMacro())
 484     return;
 485
 486   SourceLocation DefLoc = MI->getDefinitionLoc();
 487   if (DirectivesOnly && !MI->isUsed()) {
 488     SourceManager &SM = PP.getSourceManager();
 489     if (SM.isWrittenInBuiltinFile(DefLoc) ||
 490         SM.isWrittenInCommandLineFile(DefLoc))
 491       return;
 492   }
 493   MoveToLine(DefLoc, /*RequireStartOfLine=*/true);
 494   PrintMacroDefinition(*MacroNameTok.getIdentifierInfo(), *MI, PP, OS);
 495   setEmittedDirectiveOnThisLine();
 496 }
 497
 498 void PrintPPOutputPPCallbacks::MacroUndefined(const Token &MacroNameTok,
 499                                               const MacroDefinition &MD,
 500                                               const MacroDirective *Undef) {
 501   // Print out macro definitions in -dD mode and when we have -fdirectives-only
 502   // for C++20 header units.
 503   if (!DumpDefines && !DirectivesOnly)
 504     return;
 505
 506   MoveToLine(MacroNameTok.getLocation(), /*RequireStartOfLine=*/true);
 507   *OS << "#undef " << MacroNameTok.getIdentifierInfo()->getName();
 508   setEmittedDirectiveOnThisLine();
 509 }
 510
 511 static void outputPrintable(raw_ostream *OS, StringRef Str) {
 512   for (unsigned char Char : Str) {
 513     if (isPrintable(Char) && Char != '\\' && Char != '"')
 514       *OS << (char)Char;
 515     else // Output anything hard as an octal escape.
 516       *OS << '\\'
 517           << (char)('0' + ((Char >> 6) & 7))
 518           << (char)('0' + ((Char >> 3) & 7))
 519           << (char)('0' + ((Char >> 0) & 7));
 520   }
 521 }
 522
 523 void PrintPPOutputPPCallbacks::PragmaMessage(SourceLocation Loc,
 524                                              StringRef Namespace,
 525                                              PragmaMessageKind Kind,
 526                                              StringRef Str) {
 527   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 528   *OS << "#pragma ";
 529   if (!Namespace.empty())
 530     *OS << Namespace << ' ';
 531   switch (Kind) {
 532     case PMK_Message:
 533       *OS << "message(\"";
 534       break;
 535     case PMK_Warning:
 536       *OS << "warning \"";
 537       break;
 538     case PMK_Error:
 539       *OS << "error \"";
 540       break;
 541   }
 542
 543   outputPrintable(OS, Str);
 544   *OS << '"';
 545   if (Kind == PMK_Message)
 546     *OS << ')';
 547   setEmittedDirectiveOnThisLine();
 548 }
 549
 550 void PrintPPOutputPPCallbacks::PragmaDebug(SourceLocation Loc,
 551                                            StringRef DebugType) {
 552   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 553
 554   *OS << "#pragma clang __debug ";
 555   *OS << DebugType;
 556
 557   setEmittedDirectiveOnThisLine();
 558 }
 559
 560 void PrintPPOutputPPCallbacks::
 561 PragmaDiagnosticPush(SourceLocation Loc, StringRef Namespace) {
 562   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 563   *OS << "#pragma " << Namespace << " diagnostic push";
 564   setEmittedDirectiveOnThisLine();
 565 }
 566
 567 void PrintPPOutputPPCallbacks::
 568 PragmaDiagnosticPop(SourceLocation Loc, StringRef Namespace) {
 569   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 570   *OS << "#pragma " << Namespace << " diagnostic pop";
 571   setEmittedDirectiveOnThisLine();
 572 }
 573
 574 void PrintPPOutputPPCallbacks::PragmaDiagnostic(SourceLocation Loc,
 575                                                 StringRef Namespace,
 576                                                 diag::Severity Map,
 577                                                 StringRef Str) {
 578   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 579   *OS << "#pragma " << Namespace << " diagnostic ";
 580   switch (Map) {
 581   case diag::Severity::Remark:
 582     *OS << "remark";
 583     break;
 584   case diag::Severity::Warning:
 585     *OS << "warning";
 586     break;
 587   case diag::Severity::Error:
 588     *OS << "error";
 589     break;
 590   case diag::Severity::Ignored:
 591     *OS << "ignored";
 592     break;
 593   case diag::Severity::Fatal:
 594     *OS << "fatal";
 595     break;
 596   }
 597   *OS << " \"" << Str << '"';
 598   setEmittedDirectiveOnThisLine();
 599 }
 600
 601 void PrintPPOutputPPCallbacks::PragmaWarning(SourceLocation Loc,
 602                                              PragmaWarningSpecifier WarningSpec,
 603                                              ArrayRef<int> Ids) {
 604   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 605
 606   *OS << "#pragma warning(";
 607   switch(WarningSpec) {
 608     case PWS_Default:  *OS << "default"; break;
 609     case PWS_Disable:  *OS << "disable"; break;
 610     case PWS_Error:    *OS << "error"; break;
 611     case PWS_Once:     *OS << "once"; break;
 612     case PWS_Suppress: *OS << "suppress"; break;
 613     case PWS_Level1:   *OS << '1'; break;
 614     case PWS_Level2:   *OS << '2'; break;
 615     case PWS_Level3:   *OS << '3'; break;
 616     case PWS_Level4:   *OS << '4'; break;
 617   }
 618   *OS << ':';
 619
 620   for (ArrayRef<int>::iterator I = Ids.begin(), E = Ids.end(); I != E; ++I)
 621     *OS << ' ' << *I;
 622   *OS << ')';
 623   setEmittedDirectiveOnThisLine();
 624 }
 625
 626 void PrintPPOutputPPCallbacks::PragmaWarningPush(SourceLocation Loc,
 627                                                  int Level) {
 628   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 629   *OS << "#pragma warning(push";
 630   if (Level >= 0)
 631     *OS << ", " << Level;
 632   *OS << ')';
 633   setEmittedDirectiveOnThisLine();
 634 }
 635
 636 void PrintPPOutputPPCallbacks::PragmaWarningPop(SourceLocation Loc) {
 637   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 638   *OS << "#pragma warning(pop)";
 639   setEmittedDirectiveOnThisLine();
 640 }
 641
 642 void PrintPPOutputPPCallbacks::PragmaExecCharsetPush(SourceLocation Loc,
 643                                                      StringRef Str) {
 644   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 645   *OS << "#pragma character_execution_set(push";
 646   if (!Str.empty())
 647     *OS << ", " << Str;
 648   *OS << ')';
 649   setEmittedDirectiveOnThisLine();
 650 }
 651
 652 void PrintPPOutputPPCallbacks::PragmaExecCharsetPop(SourceLocation Loc) {
 653   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 654   *OS << "#pragma character_execution_set(pop)";
 655   setEmittedDirectiveOnThisLine();
 656 }
 657
 658 void PrintPPOutputPPCallbacks::
 659 PragmaAssumeNonNullBegin(SourceLocation Loc) {
 660   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 661   *OS << "#pragma clang assume_nonnull begin";
 662   setEmittedDirectiveOnThisLine();
 663 }
 664
 665 void PrintPPOutputPPCallbacks::
 666 PragmaAssumeNonNullEnd(SourceLocation Loc) {
 667   MoveToLine(Loc, /*RequireStartOfLine=*/true);
 668   *OS << "#pragma clang assume_nonnull end";
 669   setEmittedDirectiveOnThisLine();
 670 }
 671
 672 void PrintPPOutputPPCallbacks::HandleWhitespaceBeforeTok(const Token &Tok,
 673                                                          bool RequireSpace,
 674                                                          bool RequireSameLine) {
 675   // These tokens are not expanded to anything and don't need whitespace before
 676   // them.
 677   if (Tok.is(tok::eof) ||
 678       (Tok.isAnnotation() && !Tok.is(tok::annot_header_unit) &&
 679        !Tok.is(tok::annot_module_begin) && !Tok.is(tok::annot_module_end) &&
 680        !Tok.is(tok::annot_repl_input_end)))
 681     return;
 682
 683   // EmittedDirectiveOnThisLine takes priority over RequireSameLine.
 684   if ((!RequireSameLine || EmittedDirectiveOnThisLine) &&
 685       MoveToLine(Tok, /*RequireStartOfLine=*/EmittedDirectiveOnThisLine)) {
 686     if (MinimizeWhitespace) {
 687       // Avoid interpreting hash as a directive under -fpreprocessed.
 688       if (Tok.is(tok::hash))
 689         *OS << ' ';
 690     } else {
 691       // Print out space characters so that the first token on a line is
 692       // indented for easy reading.
 693       unsigned ColNo = SM.getExpansionColumnNumber(Tok.getLocation());
 694
 695       // The first token on a line can have a column number of 1, yet still
 696       // expect leading white space, if a macro expansion in column 1 starts
 697       // with an empty macro argument, or an empty nested macro expansion. In
 698       // this case, move the token to column 2.
 699       if (ColNo == 1 && Tok.hasLeadingSpace())
 700         ColNo = 2;
 701
 702       // This hack prevents stuff like:
 703       // #define HASH #
 704       // HASH define foo bar
 705       // From having the # character end up at column 1, which makes it so it
 706       // is not handled as a #define next time through the preprocessor if in
 707       // -fpreprocessed mode.
 708       if (ColNo <= 1 && Tok.is(tok::hash))
 709         *OS << ' ';
 710
 711       // Otherwise, indent the appropriate number of spaces.
 712       for (; ColNo > 1; --ColNo)
 713         *OS << ' ';
 714     }
 715   } else {
 716     // Insert whitespace between the previous and next token if either
 717     // - The caller requires it
 718     // - The input had whitespace between them and we are not in
 719     //   whitespace-minimization mode
 720     // - The whitespace is necessary to keep the tokens apart and there is not
 721     //   already a newline between them
 722     if (RequireSpace || (!MinimizeWhitespace && Tok.hasLeadingSpace()) ||
 723         ((EmittedTokensOnThisLine || EmittedDirectiveOnThisLine) &&
 724          AvoidConcat(PrevPrevTok, PrevTok, Tok)))
 725       *OS << ' ';
 726   }
 727
 728   PrevPrevTok = PrevTok;
 729   PrevTok = Tok;
 730 }
 731
 732 void PrintPPOutputPPCallbacks::HandleNewlinesInToken(const char *TokStr,
 733                                                      unsigned Len) {
 734   unsigned NumNewlines = 0;
 735   for (; Len; --Len, ++TokStr) {
 736     if (*TokStr != '\n' &&
 737         *TokStr != '\r')
 738       continue;
 739
 740     ++NumNewlines;
 741
 742     // If we have \n\r or \r\n, skip both and count as one line.
 743     if (Len != 1 &&
 744         (TokStr[1] == '\n' || TokStr[1] == '\r') &&
 745         TokStr[0] != TokStr[1]) {
 746       ++TokStr;
 747       --Len;
 748     }
 749   }
 750
 751   if (NumNewlines == 0) return;
 752
 753   CurLine += NumNewlines;
 754 }
 755
 756
 757 namespace {
 758 struct UnknownPragmaHandler : public PragmaHandler {
 759   const char *Prefix;
 760   PrintPPOutputPPCallbacks *Callbacks;
 761
 762   // Set to true if tokens should be expanded
 763   bool ShouldExpandTokens;
 764
 765   UnknownPragmaHandler(const char *prefix, PrintPPOutputPPCallbacks *callbacks,
 766                        bool RequireTokenExpansion)
 767       : Prefix(prefix), Callbacks(callbacks),
 768         ShouldExpandTokens(RequireTokenExpansion) {}
 769   void HandlePragma(Preprocessor &PP, PragmaIntroducer Introducer,
 770                     Token &PragmaTok) override {
 771     // Figure out what line we went to and insert the appropriate number of
 772     // newline characters.
 773     Callbacks->MoveToLine(PragmaTok.getLocation(), /*RequireStartOfLine=*/true);
 774     Callbacks->OS->write(Prefix, strlen(Prefix));
 775     Callbacks->setEmittedTokensOnThisLine();
 776
 777     if (ShouldExpandTokens) {
 778       // The first token does not have expanded macros. Expand them, if
 779       // required.
 780       auto Toks = std::make_unique<Token[]>(1);
 781       Toks[0] = PragmaTok;
 782       PP.EnterTokenStream(std::move(Toks), /*NumToks=*/1,
 783                           /*DisableMacroExpansion=*/false,
 784                           /*IsReinject=*/false);
 785       PP.Lex(PragmaTok);
 786     }
 787
 788     // Read and print all of the pragma tokens.
 789     bool IsFirst = true;
 790     while (PragmaTok.isNot(tok::eod)) {
 791       Callbacks->HandleWhitespaceBeforeTok(PragmaTok, /*RequireSpace=*/IsFirst,
 792                                            /*RequireSameLine=*/true);
 793       IsFirst = false;
 794       std::string TokSpell = PP.getSpelling(PragmaTok);
 795       Callbacks->OS->write(&TokSpell[0], TokSpell.size());
 796       Callbacks->setEmittedTokensOnThisLine();
 797
 798       if (ShouldExpandTokens)
 799         PP.Lex(PragmaTok);
 800       else
 801         PP.LexUnexpandedToken(PragmaTok);
 802     }
 803     Callbacks->setEmittedDirectiveOnThisLine();
 804   }
 805 };
 806 } // end anonymous namespace
 807
 808
 809 static void PrintPreprocessedTokens(Preprocessor &PP, Token &Tok,
 810                                     PrintPPOutputPPCallbacks *Callbacks) {
 811   bool DropComments = PP.getLangOpts().TraditionalCPP &&
 812                       !PP.getCommentRetentionState();
 813
 814   bool IsStartOfLine = false;
 815   char Buffer[256];
 816   while (true) {
 817     // Two lines joined with line continuation ('\' as last character on the
 818     // line) must be emitted as one line even though Tok.getLine() returns two
 819     // different values. In this situation Tok.isAtStartOfLine() is false even
 820     // though it may be the first token on the lexical line. When
 821     // dropping/skipping a token that is at the start of a line, propagate the
 822     // start-of-line-ness to the next token to not append it to the previous
 823     // line.
 824     IsStartOfLine = IsStartOfLine || Tok.isAtStartOfLine();
 825
 826     Callbacks->HandleWhitespaceBeforeTok(Tok, /*RequireSpace=*/false,
 827                                          /*RequireSameLine=*/!IsStartOfLine);
 828
 829     if (DropComments && Tok.is(tok::comment)) {
 830       // Skip comments. Normally the preprocessor does not generate
 831       // tok::comment nodes at all when not keeping comments, but under
 832       // -traditional-cpp the lexer keeps /all/ whitespace, including comments.
 833       PP.Lex(Tok);
 834       continue;
 835     } else if (Tok.is(tok::annot_repl_input_end)) {
 836       PP.Lex(Tok);
 837       continue;
 838     } else if (Tok.is(tok::eod)) {
 839       // Don't print end of directive tokens, since they are typically newlines
 840       // that mess up our line tracking. These come from unknown pre-processor
 841       // directives or hash-prefixed comments in standalone assembly files.
 842       PP.Lex(Tok);
 843       // FIXME: The token on the next line after #include should have
 844       // Tok.isAtStartOfLine() set.
 845       IsStartOfLine = true;
 846       continue;
 847     } else if (Tok.is(tok::annot_module_include)) {
 848       // PrintPPOutputPPCallbacks::InclusionDirective handles producing
 849       // appropriate output here. Ignore this token entirely.
 850       PP.Lex(Tok);
 851       IsStartOfLine = true;
 852       continue;
 853     } else if (Tok.is(tok::annot_module_begin)) {
 854       // FIXME: We retrieve this token after the FileChanged callback, and
 855       // retrieve the module_end token before the FileChanged callback, so
 856       // we render this within the file and render the module end outside the
 857       // file, but this is backwards from the token locations: the module_begin
 858       // token is at the include location (outside the file) and the module_end
 859       // token is at the EOF location (within the file).
 860       Callbacks->BeginModule(
 861           reinterpret_cast<Module *>(Tok.getAnnotationValue()));
 862       PP.Lex(Tok);
 863       IsStartOfLine = true;
 864       continue;
 865     } else if (Tok.is(tok::annot_module_end)) {
 866       Callbacks->EndModule(
 867           reinterpret_cast<Module *>(Tok.getAnnotationValue()));
 868       PP.Lex(Tok);
 869       IsStartOfLine = true;
 870       continue;
 871     } else if (Tok.is(tok::annot_header_unit)) {
 872       // This is a header-name that has been (effectively) converted into a
 873       // module-name.
 874       // FIXME: The module name could contain non-identifier module name
 875       // components. We don't have a good way to round-trip those.
 876       Module *M = reinterpret_cast<Module *>(Tok.getAnnotationValue());
 877       std::string Name = M->getFullModuleName();
 878       Callbacks->OS->write(Name.data(), Name.size());
 879       Callbacks->HandleNewlinesInToken(Name.data(), Name.size());
 880     } else if (Tok.isAnnotation()) {
 881       // Ignore annotation tokens created by pragmas - the pragmas themselves
 882       // will be reproduced in the preprocessed output.
 883       PP.Lex(Tok);
 884       continue;
 885     } else if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
 886       *Callbacks->OS << II->getName();
 887     } else if (Tok.isLiteral() && !Tok.needsCleaning() &&
 888                Tok.getLiteralData()) {
 889       Callbacks->OS->write(Tok.getLiteralData(), Tok.getLength());
 890     } else if (Tok.getLength() < std::size(Buffer)) {
 891       const char *TokPtr = Buffer;
 892       unsigned Len = PP.getSpelling(Tok, TokPtr);
 893       Callbacks->OS->write(TokPtr, Len);
 894
 895       // Tokens that can contain embedded newlines need to adjust our current
 896       // line number.
 897       // FIXME: The token may end with a newline in which case
 898       // setEmittedDirectiveOnThisLine/setEmittedTokensOnThisLine afterwards is
 899       // wrong.
 900       if (Tok.getKind() == tok::comment || Tok.getKind() == tok::unknown)
 901         Callbacks->HandleNewlinesInToken(TokPtr, Len);
 902       if (Tok.is(tok::comment) && Len >= 2 && TokPtr[0] == '/' &&
 903           TokPtr[1] == '/') {
 904         // It's a line comment;
 905         // Ensure that we don't concatenate anything behind it.
 906         Callbacks->setEmittedDirectiveOnThisLine();
 907       }
 908     } else {
 909       std::string S = PP.getSpelling(Tok);
 910       Callbacks->OS->write(S.data(), S.size());
 911
 912       // Tokens that can contain embedded newlines need to adjust our current
 913       // line number.
 914       if (Tok.getKind() == tok::comment || Tok.getKind() == tok::unknown)
 915         Callbacks->HandleNewlinesInToken(S.data(), S.size());
 916       if (Tok.is(tok::comment) && S.size() >= 2 && S[0] == '/' && S[1] == '/') {
 917         // It's a line comment;
 918         // Ensure that we don't concatenate anything behind it.
 919         Callbacks->setEmittedDirectiveOnThisLine();
 920       }
 921     }
 922     Callbacks->setEmittedTokensOnThisLine();
 923     IsStartOfLine = false;
 924
 925     if (Tok.is(tok::eof)) break;
 926
 927     PP.Lex(Tok);
 928   }
 929 }
 930
 931 typedef std::pair<const IdentifierInfo *, MacroInfo *> id_macro_pair;
 932 static int MacroIDCompare(const id_macro_pair *LHS, const id_macro_pair *RHS) {
 933   return LHS->first->getName().compare(RHS->first->getName());
 934 }
 935
 936 static void DoPrintMacros(Preprocessor &PP, raw_ostream *OS) {
 937   // Ignore unknown pragmas.
 938   PP.IgnorePragmas();
 939
 940   // -dM mode just scans and ignores all tokens in the files, then dumps out
 941   // the macro table at the end.
 942   PP.EnterMainSourceFile();
 943
 944   Token Tok;
 945   do PP.Lex(Tok);
 946   while (Tok.isNot(tok::eof));
 947
 948   SmallVector<id_macro_pair, 128> MacrosByID;
 949   for (Preprocessor::macro_iterator I = PP.macro_begin(), E = PP.macro_end();
 950        I != E; ++I) {
 951     auto *MD = I->second.getLatest();
 952     if (MD && MD->isDefined())
 953       MacrosByID.push_back(id_macro_pair(I->first, MD->getMacroInfo()));
 954   }
 955   llvm::array_pod_sort(MacrosByID.begin(), MacrosByID.end(), MacroIDCompare);
 956
 957   for (unsigned i = 0, e = MacrosByID.size(); i != e; ++i) {
 958     MacroInfo &MI = *MacrosByID[i].second;
 959     // Ignore computed macros like __LINE__ and friends.
 960     if (MI.isBuiltinMacro()) continue;
 961
 962     PrintMacroDefinition(*MacrosByID[i].first, MI, PP, OS);
 963     *OS << '\n';
 964   }
 965 }
 966
 967 /// DoPrintPreprocessedInput - This implements -E mode.
 968 ///
 969 void clang::DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
 970                                      const PreprocessorOutputOptions &Opts) {
 971   // Show macros with no output is handled specially.
 972   if (!Opts.ShowCPP) {
 973     assert(Opts.ShowMacros && "Not yet implemented!");
 974     DoPrintMacros(PP, OS);
 975     return;
 976   }
 977
 978   // Inform the preprocessor whether we want it to retain comments or not, due
 979   // to -C or -CC.
 980   PP.SetCommentRetentionState(Opts.ShowComments, Opts.ShowMacroComments);
 981
 982   PrintPPOutputPPCallbacks *Callbacks = new PrintPPOutputPPCallbacks(
 983       PP, OS, !Opts.ShowLineMarkers, Opts.ShowMacros,
 984       Opts.ShowIncludeDirectives, Opts.UseLineDirectives,
 985       Opts.MinimizeWhitespace, Opts.DirectivesOnly, Opts.KeepSystemIncludes);
 986
 987   // Expand macros in pragmas with -fms-extensions.  The assumption is that
 988   // the majority of pragmas in such a file will be Microsoft pragmas.
 989   // Remember the handlers we will add so that we can remove them later.
 990   std::unique_ptr<UnknownPragmaHandler> MicrosoftExtHandler(
 991       new UnknownPragmaHandler(
 992           "#pragma", Callbacks,
 993           /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));
 994
 995   std::unique_ptr<UnknownPragmaHandler> GCCHandler(new UnknownPragmaHandler(
 996       "#pragma GCC", Callbacks,
 997       /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));
 998
 999   std::unique_ptr<UnknownPragmaHandler> ClangHandler(new UnknownPragmaHandler(
1000       "#pragma clang", Callbacks,
1001       /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));
1002
1003   PP.AddPragmaHandler(MicrosoftExtHandler.get());
1004   PP.AddPragmaHandler("GCC", GCCHandler.get());
1005   PP.AddPragmaHandler("clang", ClangHandler.get());
1006
1007   // The tokens after pragma omp need to be expanded.
1008   //
1009   //  OpenMP [2.1, Directive format]
1010   //  Preprocessing tokens following the #pragma omp are subject to macro
1011   //  replacement.
1012   std::unique_ptr<UnknownPragmaHandler> OpenMPHandler(
1013       new UnknownPragmaHandler("#pragma omp", Callbacks,
1014                                /*RequireTokenExpansion=*/true));
1015   PP.AddPragmaHandler("omp", OpenMPHandler.get());
1016
1017   PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(Callbacks));
1018
1019   // After we have configured the preprocessor, enter the main file.
1020   PP.EnterMainSourceFile();
1021   if (Opts.DirectivesOnly)
1022     PP.SetMacroExpansionOnlyInDirectives();
1023
1024   // Consume all of the tokens that come from the predefines buffer.  Those
1025   // should not be emitted into the output and are guaranteed to be at the
1026   // start.
1027   const SourceManager &SourceMgr = PP.getSourceManager();
1028   Token Tok;
1029   do {
1030     PP.Lex(Tok);
1031     if (Tok.is(tok::eof) || !Tok.getLocation().isFileID())
1032       break;
1033
1034     PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());
1035     if (PLoc.isInvalid())
1036       break;
1037
1038     if (strcmp(PLoc.getFilename(), "<built-in>"))
1039       break;
1040   } while (true);
1041
1042   // Read all the preprocessed tokens, printing them out to the stream.
1043   PrintPreprocessedTokens(PP, Tok, Callbacks);
1044   *OS << '\n';
1045
1046   // Remove the handlers we just added to leave the preprocessor in a sane state
1047   // so that it can be reused (for example by a clang::Parser instance).
1048   PP.RemovePragmaHandler(MicrosoftExtHandler.get());
1049   PP.RemovePragmaHandler("GCC", GCCHandler.get());
1050   PP.RemovePragmaHandler("clang", ClangHandler.get());
1051   PP.RemovePragmaHandler("omp", OpenMPHandler.get());
1052 }