lib/MC/MCAsmStreamer.cpp

   1 //===- lib/MC/MCAsmStreamer.cpp - Text Assembly Output ----------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9
  10 #include "llvm/ADT/STLExtras.h"
  11 #include "llvm/ADT/SmallString.h"
  12 #include "llvm/ADT/StringExtras.h"
  13 #include "llvm/ADT/Twine.h"
  14 #include "llvm/MC/MCAsmBackend.h"
  15 #include "llvm/MC/MCAsmInfo.h"
  16 #include "llvm/MC/MCCodeEmitter.h"
  17 #include "llvm/MC/MCCodeView.h"
  18 #include "llvm/MC/MCContext.h"
  19 #include "llvm/MC/MCExpr.h"
  20 #include "llvm/MC/MCFixupKindInfo.h"
  21 #include "llvm/MC/MCInst.h"
  22 #include "llvm/MC/MCInstPrinter.h"
  23 #include "llvm/MC/MCObjectFileInfo.h"
  24 #include "llvm/MC/MCRegisterInfo.h"
  25 #include "llvm/MC/MCSectionCOFF.h"
  26 #include "llvm/MC/MCSectionMachO.h"
  27 #include "llvm/MC/MCStreamer.h"
  28 #include "llvm/MC/MCSymbolELF.h"
  29 #include "llvm/Support/ErrorHandling.h"
  30 #include "llvm/Support/Format.h"
  31 #include "llvm/Support/FormattedStream.h"
  32 #include "llvm/Support/LEB128.h"
  33 #include "llvm/Support/MathExtras.h"
  34 #include "llvm/Support/Path.h"
  35 #include "llvm/Support/SourceMgr.h"
  36 #include <cctype>
  37
  38 using namespace llvm;
  39
  40 namespace {
  41
  42 class MCAsmStreamer final : public MCStreamer {
  43   std::unique_ptr<formatted_raw_ostream> OSOwner;
  44   formatted_raw_ostream &OS;
  45   const MCAsmInfo *MAI;
  46   std::unique_ptr<MCInstPrinter> InstPrinter;
  47   std::unique_ptr<MCCodeEmitter> Emitter;
  48   std::unique_ptr<MCAsmBackend> AsmBackend;
  49
  50   SmallString<128> ExplicitCommentToEmit;
  51   SmallString<128> CommentToEmit;
  52   raw_svector_ostream CommentStream;
  53
  54   unsigned IsVerboseAsm : 1;
  55   unsigned ShowInst : 1;
  56   unsigned UseDwarfDirectory : 1;
  57
  58   void EmitRegisterName(int64_t Register);
  59   void EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) override;
  60   void EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) override;
  61
  62 public:
  63   MCAsmStreamer(MCContext &Context, std::unique_ptr<formatted_raw_ostream> os,
  64                 bool isVerboseAsm, bool useDwarfDirectory,
  65                 MCInstPrinter *printer, MCCodeEmitter *emitter,
  66                 MCAsmBackend *asmbackend, bool showInst)
  67       : MCStreamer(Context), OSOwner(std::move(os)), OS(*OSOwner),
  68         MAI(Context.getAsmInfo()), InstPrinter(printer), Emitter(emitter),
  69         AsmBackend(asmbackend), CommentStream(CommentToEmit),
  70         IsVerboseAsm(isVerboseAsm), ShowInst(showInst),
  71         UseDwarfDirectory(useDwarfDirectory) {
  72     assert(InstPrinter);
  73     if (IsVerboseAsm)
  74         InstPrinter->setCommentStream(CommentStream);
  75   }
  76
  77   inline void EmitEOL() {
  78     // Dump Explicit Comments here.
  79     emitExplicitComments();
  80     // If we don't have any comments, just emit a \n.
  81     if (!IsVerboseAsm) {
  82       OS << '\n';
  83       return;
  84     }
  85     EmitCommentsAndEOL();
  86   }
  87
  88   void EmitSyntaxDirective() override;
  89
  90   void EmitCommentsAndEOL();
  91
  92   /// isVerboseAsm - Return true if this streamer supports verbose assembly at
  93   /// all.
  94   bool isVerboseAsm() const override { return IsVerboseAsm; }
  95
  96   /// hasRawTextSupport - We support EmitRawText.
  97   bool hasRawTextSupport() const override { return true; }
  98
  99   /// AddComment - Add a comment that can be emitted to the generated .s
 100   /// file if applicable as a QoI issue to make the output of the compiler
 101   /// more readable.  This only affects the MCAsmStreamer, and only when
 102   /// verbose assembly output is enabled.
 103   void AddComment(const Twine &T, bool EOL = true) override;
 104
 105   /// AddEncodingComment - Add a comment showing the encoding of an instruction.
 106   /// If PrintSchedInfo - is true then the comment sched:[x:y] should
 107   //    be added to output if it's being supported by target
 108   void AddEncodingComment(const MCInst &Inst, const MCSubtargetInfo &,
 109                           bool PrintSchedInfo);
 110
 111   /// GetCommentOS - Return a raw_ostream that comments can be written to.
 112   /// Unlike AddComment, you are required to terminate comments with \n if you
 113   /// use this method.
 114   raw_ostream &GetCommentOS() override {
 115     if (!IsVerboseAsm)
 116       return nulls();  // Discard comments unless in verbose asm mode.
 117     return CommentStream;
 118   }
 119
 120   void emitRawComment(const Twine &T, bool TabPrefix = true) override;
 121
 122   void addExplicitComment(const Twine &T) override;
 123   void emitExplicitComments() override;
 124
 125   /// AddBlankLine - Emit a blank line to a .s file to pretty it up.
 126   void AddBlankLine() override {
 127     EmitEOL();
 128   }
 129
 130   /// @name MCStreamer Interface
 131   /// @{
 132
 133   void ChangeSection(MCSection *Section, const MCExpr *Subsection) override;
 134
 135   void EmitLOHDirective(MCLOHType Kind, const MCLOHArgs &Args) override;
 136   void EmitLabel(MCSymbol *Symbol, SMLoc Loc = SMLoc()) override;
 137
 138   void EmitAssemblerFlag(MCAssemblerFlag Flag) override;
 139   void EmitLinkerOptions(ArrayRef<std::string> Options) override;
 140   void EmitDataRegion(MCDataRegionType Kind) override;
 141   void EmitVersionMin(MCVersionMinType Kind, unsigned Major, unsigned Minor,
 142                       unsigned Update) override;
 143   void EmitThumbFunc(MCSymbol *Func) override;
 144
 145   void EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) override;
 146   void EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) override;
 147   bool EmitSymbolAttribute(MCSymbol *Symbol, MCSymbolAttr Attribute) override;
 148
 149   void EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) override;
 150   void BeginCOFFSymbolDef(const MCSymbol *Symbol) override;
 151   void EmitCOFFSymbolStorageClass(int StorageClass) override;
 152   void EmitCOFFSymbolType(int Type) override;
 153   void EndCOFFSymbolDef() override;
 154   void EmitCOFFSafeSEH(MCSymbol const *Symbol) override;
 155   void EmitCOFFSectionIndex(MCSymbol const *Symbol) override;
 156   void EmitCOFFSecRel32(MCSymbol const *Symbol, uint64_t Offset) override;
 157   void emitELFSize(MCSymbol *Symbol, const MCExpr *Value) override;
 158   void EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
 159                         unsigned ByteAlignment) override;
 160
 161   /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
 162   ///
 163   /// @param Symbol - The common symbol to emit.
 164   /// @param Size - The size of the common symbol.
 165   /// @param ByteAlignment - The alignment of the common symbol in bytes.
 166   void EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
 167                              unsigned ByteAlignment) override;
 168
 169   void EmitZerofill(MCSection *Section, MCSymbol *Symbol = nullptr,
 170                     uint64_t Size = 0, unsigned ByteAlignment = 0) override;
 171
 172   void EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol, uint64_t Size,
 173                       unsigned ByteAlignment = 0) override;
 174
 175   void EmitBinaryData(StringRef Data) override;
 176
 177   void EmitBytes(StringRef Data) override;
 178
 179   void EmitValueImpl(const MCExpr *Value, unsigned Size,
 180                      SMLoc Loc = SMLoc()) override;
 181   void EmitIntValue(uint64_t Value, unsigned Size) override;
 182
 183   void EmitULEB128Value(const MCExpr *Value) override;
 184
 185   void EmitSLEB128Value(const MCExpr *Value) override;
 186
 187   void EmitDTPRel32Value(const MCExpr *Value) override;
 188   void EmitDTPRel64Value(const MCExpr *Value) override;
 189   void EmitTPRel32Value(const MCExpr *Value) override;
 190   void EmitTPRel64Value(const MCExpr *Value) override;
 191
 192   void EmitGPRel64Value(const MCExpr *Value) override;
 193
 194   void EmitGPRel32Value(const MCExpr *Value) override;
 195
 196
 197   void emitFill(uint64_t NumBytes, uint8_t FillValue) override;
 198
 199   void emitFill(const MCExpr &NumBytes, uint64_t FillValue,
 200                 SMLoc Loc = SMLoc()) override;
 201
 202   void emitFill(uint64_t NumValues, int64_t Size, int64_t Expr) override;
 203
 204   void emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
 205                 SMLoc Loc = SMLoc()) override;
 206
 207   void EmitValueToAlignment(unsigned ByteAlignment, int64_t Value = 0,
 208                             unsigned ValueSize = 1,
 209                             unsigned MaxBytesToEmit = 0) override;
 210
 211   void EmitCodeAlignment(unsigned ByteAlignment,
 212                          unsigned MaxBytesToEmit = 0) override;
 213
 214   void emitValueToOffset(const MCExpr *Offset,
 215                          unsigned char Value,
 216                          SMLoc Loc) override;
 217
 218   void EmitFileDirective(StringRef Filename) override;
 219   unsigned EmitDwarfFileDirective(unsigned FileNo, StringRef Directory,
 220                                   StringRef Filename,
 221                                   unsigned CUID = 0) override;
 222   void EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
 223                              unsigned Column, unsigned Flags,
 224                              unsigned Isa, unsigned Discriminator,
 225                              StringRef FileName) override;
 226   MCSymbol *getDwarfLineTableSymbol(unsigned CUID) override;
 227
 228   bool EmitCVFileDirective(unsigned FileNo, StringRef Filename,
 229                            ArrayRef<uint8_t> Checksum,
 230                            unsigned ChecksumKind) override;
 231   bool EmitCVFuncIdDirective(unsigned FuncId) override;
 232   bool EmitCVInlineSiteIdDirective(unsigned FunctionId, unsigned IAFunc,
 233                                    unsigned IAFile, unsigned IALine,
 234                                    unsigned IACol, SMLoc Loc) override;
 235   void EmitCVLocDirective(unsigned FunctionId, unsigned FileNo, unsigned Line,
 236                           unsigned Column, bool PrologueEnd, bool IsStmt,
 237                           StringRef FileName, SMLoc Loc) override;
 238   void EmitCVLinetableDirective(unsigned FunctionId, const MCSymbol *FnStart,
 239                                 const MCSymbol *FnEnd) override;
 240   void EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
 241                                       unsigned SourceFileId,
 242                                       unsigned SourceLineNum,
 243                                       const MCSymbol *FnStartSym,
 244                                       const MCSymbol *FnEndSym) override;
 245   void EmitCVDefRangeDirective(
 246       ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
 247       StringRef FixedSizePortion) override;
 248   void EmitCVStringTableDirective() override;
 249   void EmitCVFileChecksumsDirective() override;
 250   void EmitCVFileChecksumOffsetDirective(unsigned FileNo) override;
 251
 252   void EmitIdent(StringRef IdentString) override;
 253   void EmitCFISections(bool EH, bool Debug) override;
 254   void EmitCFIDefCfa(int64_t Register, int64_t Offset) override;
 255   void EmitCFIDefCfaOffset(int64_t Offset) override;
 256   void EmitCFIDefCfaRegister(int64_t Register) override;
 257   void EmitCFIOffset(int64_t Register, int64_t Offset) override;
 258   void EmitCFIPersonality(const MCSymbol *Sym, unsigned Encoding) override;
 259   void EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) override;
 260   void EmitCFIRememberState() override;
 261   void EmitCFIRestoreState() override;
 262   void EmitCFISameValue(int64_t Register) override;
 263   void EmitCFIRelOffset(int64_t Register, int64_t Offset) override;
 264   void EmitCFIAdjustCfaOffset(int64_t Adjustment) override;
 265   void EmitCFIEscape(StringRef Values) override;
 266   void EmitCFIGnuArgsSize(int64_t Size) override;
 267   void EmitCFISignalFrame() override;
 268   void EmitCFIUndefined(int64_t Register) override;
 269   void EmitCFIRegister(int64_t Register1, int64_t Register2) override;
 270   void EmitCFIWindowSave() override;
 271   void EmitCFIReturnColumn(int64_t Register) override;
 272
 273   void EmitWinCFIStartProc(const MCSymbol *Symbol) override;
 274   void EmitWinCFIEndProc() override;
 275   void EmitWinCFIStartChained() override;
 276   void EmitWinCFIEndChained() override;
 277   void EmitWinCFIPushReg(unsigned Register) override;
 278   void EmitWinCFISetFrame(unsigned Register, unsigned Offset) override;
 279   void EmitWinCFIAllocStack(unsigned Size) override;
 280   void EmitWinCFISaveReg(unsigned Register, unsigned Offset) override;
 281   void EmitWinCFISaveXMM(unsigned Register, unsigned Offset) override;
 282   void EmitWinCFIPushFrame(bool Code) override;
 283   void EmitWinCFIEndProlog() override;
 284
 285   void EmitWinEHHandler(const MCSymbol *Sym, bool Unwind, bool Except) override;
 286   void EmitWinEHHandlerData() override;
 287
 288   void EmitInstruction(const MCInst &Inst, const MCSubtargetInfo &STI,
 289                        bool PrintSchedInfo) override;
 290
 291   void EmitBundleAlignMode(unsigned AlignPow2) override;
 292   void EmitBundleLock(bool AlignToEnd) override;
 293   void EmitBundleUnlock() override;
 294
 295   bool EmitRelocDirective(const MCExpr &Offset, StringRef Name,
 296                           const MCExpr *Expr, SMLoc Loc) override;
 297
 298   /// EmitRawText - If this file is backed by an assembly streamer, this dumps
 299   /// the specified string in the output .s file.  This capability is
 300   /// indicated by the hasRawTextSupport() predicate.
 301   void EmitRawTextImpl(StringRef String) override;
 302
 303   void FinishImpl() override;
 304 };
 305
 306 } // end anonymous namespace.
 307
 308 /// AddComment - Add a comment that can be emitted to the generated .s
 309 /// file if applicable as a QoI issue to make the output of the compiler
 310 /// more readable.  This only affects the MCAsmStreamer, and only when
 311 /// verbose assembly output is enabled.
 312 /// By deafult EOL is set to true so that each comment goes on its own line.
 313 void MCAsmStreamer::AddComment(const Twine &T, bool EOL) {
 314   if (!IsVerboseAsm) return;
 315
 316   T.toVector(CommentToEmit);
 317
 318   if (EOL)
 319     CommentToEmit.push_back('\n'); // Place comment in a new line.
 320 }
 321
 322 void MCAsmStreamer::EmitCommentsAndEOL() {
 323   if (CommentToEmit.empty() && CommentStream.GetNumBytesInBuffer() == 0) {
 324     OS << '\n';
 325     return;
 326   }
 327
 328   StringRef Comments = CommentToEmit;
 329
 330   assert(Comments.back() == '\n' &&
 331          "Comment array not newline terminated");
 332   do {
 333     // Emit a line of comments.
 334     OS.PadToColumn(MAI->getCommentColumn());
 335     size_t Position = Comments.find('\n');
 336     OS << MAI->getCommentString() << ' ' << Comments.substr(0, Position) <<'\n';
 337
 338     Comments = Comments.substr(Position+1);
 339   } while (!Comments.empty());
 340
 341   CommentToEmit.clear();
 342 }
 343
 344 static inline int64_t truncateToSize(int64_t Value, unsigned Bytes) {
 345   assert(Bytes > 0 && Bytes <= 8 && "Invalid size!");
 346   return Value & ((uint64_t) (int64_t) -1 >> (64 - Bytes * 8));
 347 }
 348
 349 void MCAsmStreamer::emitRawComment(const Twine &T, bool TabPrefix) {
 350   if (TabPrefix)
 351     OS << '\t';
 352   OS << MAI->getCommentString() << T;
 353   EmitEOL();
 354 }
 355
 356 void MCAsmStreamer::addExplicitComment(const Twine &T) {
 357   StringRef c = T.getSingleStringRef();
 358   if (c.equals(StringRef(MAI->getSeparatorString())))
 359     return;
 360   if (c.startswith(StringRef("//"))) {
 361     ExplicitCommentToEmit.append("\t");
 362     ExplicitCommentToEmit.append(MAI->getCommentString());
 363     // drop //
 364     ExplicitCommentToEmit.append(c.slice(2, c.size()).str());
 365   } else if (c.startswith(StringRef("/*"))) {
 366     size_t p = 2, len = c.size() - 2;
 367     // emit each line in comment as separate newline.
 368     do {
 369       size_t newp = std::min(len, c.find_first_of("\r\n", p));
 370       ExplicitCommentToEmit.append("\t");
 371       ExplicitCommentToEmit.append(MAI->getCommentString());
 372       ExplicitCommentToEmit.append(c.slice(p, newp).str());
 373       // If we have another line in this comment add line
 374       if (newp < len)
 375         ExplicitCommentToEmit.append("\n");
 376       p = newp + 1;
 377     } while (p < len);
 378   } else if (c.startswith(StringRef(MAI->getCommentString()))) {
 379     ExplicitCommentToEmit.append("\t");
 380     ExplicitCommentToEmit.append(c.str());
 381   } else if (c.front() == '#') {
 382
 383     ExplicitCommentToEmit.append("\t");
 384     ExplicitCommentToEmit.append(MAI->getCommentString());
 385     ExplicitCommentToEmit.append(c.slice(1, c.size()).str());
 386   } else
 387     assert(false && "Unexpected Assembly Comment");
 388   // full line comments immediately output
 389   if (c.back() == '\n')
 390     emitExplicitComments();
 391 }
 392
 393 void MCAsmStreamer::emitExplicitComments() {
 394   StringRef Comments = ExplicitCommentToEmit;
 395   if (!Comments.empty())
 396     OS << Comments;
 397   ExplicitCommentToEmit.clear();
 398 }
 399
 400 void MCAsmStreamer::ChangeSection(MCSection *Section,
 401                                   const MCExpr *Subsection) {
 402   assert(Section && "Cannot switch to a null section!");
 403   Section->PrintSwitchToSection(
 404       *MAI, getContext().getObjectFileInfo()->getTargetTriple(), OS,
 405       Subsection);
 406 }
 407
 408 void MCAsmStreamer::EmitLabel(MCSymbol *Symbol, SMLoc Loc) {
 409   MCStreamer::EmitLabel(Symbol, Loc);
 410
 411   Symbol->print(OS, MAI);
 412   OS << MAI->getLabelSuffix();
 413
 414   EmitEOL();
 415 }
 416
 417 void MCAsmStreamer::EmitLOHDirective(MCLOHType Kind, const MCLOHArgs &Args) {
 418   StringRef str = MCLOHIdToName(Kind);
 419
 420 #ifndef NDEBUG
 421   int NbArgs = MCLOHIdToNbArgs(Kind);
 422   assert(NbArgs != -1 && ((size_t)NbArgs) == Args.size() && "Malformed LOH!");
 423   assert(str != "" && "Invalid LOH name");
 424 #endif
 425
 426   OS << "\t" << MCLOHDirectiveName() << " " << str << "\t";
 427   bool IsFirst = true;
 428   for (const MCSymbol *Arg : Args) {
 429     if (!IsFirst)
 430       OS << ", ";
 431     IsFirst = false;
 432     Arg->print(OS, MAI);
 433   }
 434   EmitEOL();
 435 }
 436
 437 void MCAsmStreamer::EmitAssemblerFlag(MCAssemblerFlag Flag) {
 438   switch (Flag) {
 439   case MCAF_SyntaxUnified:         OS << "\t.syntax unified"; break;
 440   case MCAF_SubsectionsViaSymbols: OS << ".subsections_via_symbols"; break;
 441   case MCAF_Code16:                OS << '\t'<< MAI->getCode16Directive();break;
 442   case MCAF_Code32:                OS << '\t'<< MAI->getCode32Directive();break;
 443   case MCAF_Code64:                OS << '\t'<< MAI->getCode64Directive();break;
 444   }
 445   EmitEOL();
 446 }
 447
 448 void MCAsmStreamer::EmitLinkerOptions(ArrayRef<std::string> Options) {
 449   assert(!Options.empty() && "At least one option is required!");
 450   OS << "\t.linker_option \"" << Options[0] << '"';
 451   for (ArrayRef<std::string>::iterator it = Options.begin() + 1,
 452          ie = Options.end(); it != ie; ++it) {
 453     OS << ", " << '"' << *it << '"';
 454   }
 455   EmitEOL();
 456 }
 457
 458 void MCAsmStreamer::EmitDataRegion(MCDataRegionType Kind) {
 459   if (!MAI->doesSupportDataRegionDirectives())
 460     return;
 461   switch (Kind) {
 462   case MCDR_DataRegion:            OS << "\t.data_region"; break;
 463   case MCDR_DataRegionJT8:         OS << "\t.data_region jt8"; break;
 464   case MCDR_DataRegionJT16:        OS << "\t.data_region jt16"; break;
 465   case MCDR_DataRegionJT32:        OS << "\t.data_region jt32"; break;
 466   case MCDR_DataRegionEnd:         OS << "\t.end_data_region"; break;
 467   }
 468   EmitEOL();
 469 }
 470
 471 void MCAsmStreamer::EmitVersionMin(MCVersionMinType Kind, unsigned Major,
 472                                    unsigned Minor, unsigned Update) {
 473   switch (Kind) {
 474   case MCVM_WatchOSVersionMin:    OS << "\t.watchos_version_min"; break;
 475   case MCVM_TvOSVersionMin:       OS << "\t.tvos_version_min"; break;
 476   case MCVM_IOSVersionMin:        OS << "\t.ios_version_min"; break;
 477   case MCVM_OSXVersionMin:        OS << "\t.macosx_version_min"; break;
 478   }
 479   OS << " " << Major << ", " << Minor;
 480   if (Update)
 481     OS << ", " << Update;
 482   EmitEOL();
 483 }
 484
 485 void MCAsmStreamer::EmitThumbFunc(MCSymbol *Func) {
 486   // This needs to emit to a temporary string to get properly quoted
 487   // MCSymbols when they have spaces in them.
 488   OS << "\t.thumb_func";
 489   // Only Mach-O hasSubsectionsViaSymbols()
 490   if (MAI->hasSubsectionsViaSymbols()) {
 491     OS << '\t';
 492     Func->print(OS, MAI);
 493   }
 494   EmitEOL();
 495 }
 496
 497 void MCAsmStreamer::EmitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
 498   Symbol->print(OS, MAI);
 499   OS << " = ";
 500   Value->print(OS, MAI);
 501
 502   EmitEOL();
 503
 504   MCStreamer::EmitAssignment(Symbol, Value);
 505 }
 506
 507 void MCAsmStreamer::EmitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {
 508   OS << ".weakref ";
 509   Alias->print(OS, MAI);
 510   OS << ", ";
 511   Symbol->print(OS, MAI);
 512   EmitEOL();
 513 }
 514
 515 bool MCAsmStreamer::EmitSymbolAttribute(MCSymbol *Symbol,
 516                                         MCSymbolAttr Attribute) {
 517   switch (Attribute) {
 518   case MCSA_Invalid: llvm_unreachable("Invalid symbol attribute");
 519   case MCSA_ELF_TypeFunction:    /// .type _foo, STT_FUNC  # aka @function
 520   case MCSA_ELF_TypeIndFunction: /// .type _foo, STT_GNU_IFUNC
 521   case MCSA_ELF_TypeObject:      /// .type _foo, STT_OBJECT  # aka @object
 522   case MCSA_ELF_TypeTLS:         /// .type _foo, STT_TLS     # aka @tls_object
 523   case MCSA_ELF_TypeCommon:      /// .type _foo, STT_COMMON  # aka @common
 524   case MCSA_ELF_TypeNoType:      /// .type _foo, STT_NOTYPE  # aka @notype
 525   case MCSA_ELF_TypeGnuUniqueObject:  /// .type _foo, @gnu_unique_object
 526     if (!MAI->hasDotTypeDotSizeDirective())
 527       return false; // Symbol attribute not supported
 528     OS << "\t.type\t";
 529     Symbol->print(OS, MAI);
 530     OS << ',' << ((MAI->getCommentString()[0] != '@') ? '@' : '%');
 531     switch (Attribute) {
 532     default: return false;
 533     case MCSA_ELF_TypeFunction:    OS << "function"; break;
 534     case MCSA_ELF_TypeIndFunction: OS << "gnu_indirect_function"; break;
 535     case MCSA_ELF_TypeObject:      OS << "object"; break;
 536     case MCSA_ELF_TypeTLS:         OS << "tls_object"; break;
 537     case MCSA_ELF_TypeCommon:      OS << "common"; break;
 538     case MCSA_ELF_TypeNoType:      OS << "no_type"; break;
 539     case MCSA_ELF_TypeGnuUniqueObject: OS << "gnu_unique_object"; break;
 540     }
 541     EmitEOL();
 542     return true;
 543   case MCSA_Global: // .globl/.global
 544     OS << MAI->getGlobalDirective();
 545     break;
 546   case MCSA_Hidden:         OS << "\t.hidden\t";          break;
 547   case MCSA_IndirectSymbol: OS << "\t.indirect_symbol\t"; break;
 548   case MCSA_Internal:       OS << "\t.internal\t";        break;
 549   case MCSA_LazyReference:  OS << "\t.lazy_reference\t";  break;
 550   case MCSA_Local:          OS << "\t.local\t";           break;
 551   case MCSA_NoDeadStrip:
 552     if (!MAI->hasNoDeadStrip())
 553       return false;
 554     OS << "\t.no_dead_strip\t";
 555     break;
 556   case MCSA_SymbolResolver: OS << "\t.symbol_resolver\t"; break;
 557   case MCSA_AltEntry:       OS << "\t.alt_entry\t";       break;
 558   case MCSA_PrivateExtern:
 559     OS << "\t.private_extern\t";
 560     break;
 561   case MCSA_Protected:      OS << "\t.protected\t";       break;
 562   case MCSA_Reference:      OS << "\t.reference\t";       break;
 563   case MCSA_Weak:           OS << MAI->getWeakDirective(); break;
 564   case MCSA_WeakDefinition:
 565     OS << "\t.weak_definition\t";
 566     break;
 567       // .weak_reference
 568   case MCSA_WeakReference:  OS << MAI->getWeakRefDirective(); break;
 569   case MCSA_WeakDefAutoPrivate: OS << "\t.weak_def_can_be_hidden\t"; break;
 570   }
 571
 572   Symbol->print(OS, MAI);
 573   EmitEOL();
 574
 575   return true;
 576 }
 577
 578 void MCAsmStreamer::EmitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {
 579   OS << ".desc" << ' ';
 580   Symbol->print(OS, MAI);
 581   OS << ',' << DescValue;
 582   EmitEOL();
 583 }
 584
 585 void MCAsmStreamer::EmitSyntaxDirective() {
 586   if (MAI->getAssemblerDialect() == 1) {
 587     OS << "\t.intel_syntax noprefix";
 588     EmitEOL();
 589   }
 590   // FIXME: Currently emit unprefix'ed registers.
 591   // The intel_syntax directive has one optional argument
 592   // with may have a value of prefix or noprefix.
 593 }
 594
 595 void MCAsmStreamer::BeginCOFFSymbolDef(const MCSymbol *Symbol) {
 596   OS << "\t.def\t ";
 597   Symbol->print(OS, MAI);
 598   OS << ';';
 599   EmitEOL();
 600 }
 601
 602 void MCAsmStreamer::EmitCOFFSymbolStorageClass (int StorageClass) {
 603   OS << "\t.scl\t" << StorageClass << ';';
 604   EmitEOL();
 605 }
 606
 607 void MCAsmStreamer::EmitCOFFSymbolType (int Type) {
 608   OS << "\t.type\t" << Type << ';';
 609   EmitEOL();
 610 }
 611
 612 void MCAsmStreamer::EndCOFFSymbolDef() {
 613   OS << "\t.endef";
 614   EmitEOL();
 615 }
 616
 617 void MCAsmStreamer::EmitCOFFSafeSEH(MCSymbol const *Symbol) {
 618   OS << "\t.safeseh\t";
 619   Symbol->print(OS, MAI);
 620   EmitEOL();
 621 }
 622
 623 void MCAsmStreamer::EmitCOFFSectionIndex(MCSymbol const *Symbol) {
 624   OS << "\t.secidx\t";
 625   Symbol->print(OS, MAI);
 626   EmitEOL();
 627 }
 628
 629 void MCAsmStreamer::EmitCOFFSecRel32(MCSymbol const *Symbol, uint64_t Offset) {
 630   OS << "\t.secrel32\t";
 631   Symbol->print(OS, MAI);
 632   if (Offset != 0)
 633     OS << '+' << Offset;
 634   EmitEOL();
 635 }
 636
 637 void MCAsmStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {
 638   assert(MAI->hasDotTypeDotSizeDirective());
 639   OS << "\t.size\t";
 640   Symbol->print(OS, MAI);
 641   OS << ", ";
 642   Value->print(OS, MAI);
 643   EmitEOL();
 644 }
 645
 646 void MCAsmStreamer::EmitCommonSymbol(MCSymbol *Symbol, uint64_t Size,
 647                                      unsigned ByteAlignment) {
 648   OS << "\t.comm\t";
 649   Symbol->print(OS, MAI);
 650   OS << ',' << Size;
 651
 652   if (ByteAlignment != 0) {
 653     if (MAI->getCOMMDirectiveAlignmentIsInBytes())
 654       OS << ',' << ByteAlignment;
 655     else
 656       OS << ',' << Log2_32(ByteAlignment);
 657   }
 658   EmitEOL();
 659 }
 660
 661 /// EmitLocalCommonSymbol - Emit a local common (.lcomm) symbol.
 662 ///
 663 /// @param Symbol - The common symbol to emit.
 664 /// @param Size - The size of the common symbol.
 665 void MCAsmStreamer::EmitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
 666                                           unsigned ByteAlign) {
 667   OS << "\t.lcomm\t";
 668   Symbol->print(OS, MAI);
 669   OS << ',' << Size;
 670
 671   if (ByteAlign > 1) {
 672     switch (MAI->getLCOMMDirectiveAlignmentType()) {
 673     case LCOMM::NoAlignment:
 674       llvm_unreachable("alignment not supported on .lcomm!");
 675     case LCOMM::ByteAlignment:
 676       OS << ',' << ByteAlign;
 677       break;
 678     case LCOMM::Log2Alignment:
 679       assert(isPowerOf2_32(ByteAlign) && "alignment must be a power of 2");
 680       OS << ',' << Log2_32(ByteAlign);
 681       break;
 682     }
 683   }
 684   EmitEOL();
 685 }
 686
 687 void MCAsmStreamer::EmitZerofill(MCSection *Section, MCSymbol *Symbol,
 688                                  uint64_t Size, unsigned ByteAlignment) {
 689   if (Symbol)
 690     AssignFragment(Symbol, &Section->getDummyFragment());
 691
 692   // Note: a .zerofill directive does not switch sections.
 693   OS << ".zerofill ";
 694
 695   // This is a mach-o specific directive.
 696   const MCSectionMachO *MOSection = ((const MCSectionMachO*)Section);
 697   OS << MOSection->getSegmentName() << "," << MOSection->getSectionName();
 698
 699   if (Symbol) {
 700     OS << ',';
 701     Symbol->print(OS, MAI);
 702     OS << ',' << Size;
 703     if (ByteAlignment != 0)
 704       OS << ',' << Log2_32(ByteAlignment);
 705   }
 706   EmitEOL();
 707 }
 708
 709 // .tbss sym, size, align
 710 // This depends that the symbol has already been mangled from the original,
 711 // e.g. _a.
 712 void MCAsmStreamer::EmitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
 713                                    uint64_t Size, unsigned ByteAlignment) {
 714   AssignFragment(Symbol, &Section->getDummyFragment());
 715
 716   assert(Symbol && "Symbol shouldn't be NULL!");
 717   // Instead of using the Section we'll just use the shortcut.
 718   // This is a mach-o specific directive and section.
 719   OS << ".tbss ";
 720   Symbol->print(OS, MAI);
 721   OS << ", " << Size;
 722
 723   // Output align if we have it.  We default to 1 so don't bother printing
 724   // that.
 725   if (ByteAlignment > 1) OS << ", " << Log2_32(ByteAlignment);
 726
 727   EmitEOL();
 728 }
 729
 730 static inline char toOctal(int X) { return (X&7)+'0'; }
 731
 732 static void PrintQuotedString(StringRef Data, raw_ostream &OS) {
 733   OS << '"';
 734
 735   for (unsigned i = 0, e = Data.size(); i != e; ++i) {
 736     unsigned char C = Data[i];
 737     if (C == '"' || C == '\\') {
 738       OS << '\\' << (char)C;
 739       continue;
 740     }
 741
 742     if (isprint((unsigned char)C)) {
 743       OS << (char)C;
 744       continue;
 745     }
 746
 747     switch (C) {
 748       case '\b': OS << "\\b"; break;
 749       case '\f': OS << "\\f"; break;
 750       case '\n': OS << "\\n"; break;
 751       case '\r': OS << "\\r"; break;
 752       case '\t': OS << "\\t"; break;
 753       default:
 754         OS << '\\';
 755         OS << toOctal(C >> 6);
 756         OS << toOctal(C >> 3);
 757         OS << toOctal(C >> 0);
 758         break;
 759     }
 760   }
 761
 762   OS << '"';
 763 }
 764
 765 void MCAsmStreamer::EmitBytes(StringRef Data) {
 766   assert(getCurrentSectionOnly() &&
 767          "Cannot emit contents before setting section!");
 768   if (Data.empty()) return;
 769
 770   if (Data.size() == 1) {
 771     OS << MAI->getData8bitsDirective();
 772     OS << (unsigned)(unsigned char)Data[0];
 773     EmitEOL();
 774     return;
 775   }
 776
 777   // If the data ends with 0 and the target supports .asciz, use it, otherwise
 778   // use .ascii
 779   if (MAI->getAscizDirective() && Data.back() == 0) {
 780     OS << MAI->getAscizDirective();
 781     Data = Data.substr(0, Data.size()-1);
 782   } else {
 783     OS << MAI->getAsciiDirective();
 784   }
 785
 786   PrintQuotedString(Data, OS);
 787   EmitEOL();
 788 }
 789
 790 void MCAsmStreamer::EmitBinaryData(StringRef Data) {
 791   // This is binary data. Print it in a grid of hex bytes for readability.
 792   const size_t Cols = 4;
 793   for (size_t I = 0, EI = alignTo(Data.size(), Cols); I < EI; I += Cols) {
 794     size_t J = I, EJ = std::min(I + Cols, Data.size());
 795     assert(EJ > 0);
 796     OS << MAI->getData8bitsDirective();
 797     for (; J < EJ - 1; ++J)
 798       OS << format("0x%02x", uint8_t(Data[J])) << ", ";
 799     OS << format("0x%02x", uint8_t(Data[J]));
 800     EmitEOL();
 801   }
 802 }
 803
 804 void MCAsmStreamer::EmitIntValue(uint64_t Value, unsigned Size) {
 805   EmitValue(MCConstantExpr::create(Value, getContext()), Size);
 806 }
 807
 808 void MCAsmStreamer::EmitValueImpl(const MCExpr *Value, unsigned Size,
 809                                   SMLoc Loc) {
 810   assert(Size <= 8 && "Invalid size");
 811   assert(getCurrentSectionOnly() &&
 812          "Cannot emit contents before setting section!");
 813   const char *Directive = nullptr;
 814   switch (Size) {
 815   default: break;
 816   case 1: Directive = MAI->getData8bitsDirective();  break;
 817   case 2: Directive = MAI->getData16bitsDirective(); break;
 818   case 4: Directive = MAI->getData32bitsDirective(); break;
 819   case 8: Directive = MAI->getData64bitsDirective(); break;
 820   }
 821
 822   if (!Directive) {
 823     int64_t IntValue;
 824     if (!Value->evaluateAsAbsolute(IntValue))
 825       report_fatal_error("Don't know how to emit this value.");
 826
 827     // We couldn't handle the requested integer size so we fallback by breaking
 828     // the request down into several, smaller, integers.
 829     // Since sizes greater or equal to "Size" are invalid, we use the greatest
 830     // power of 2 that is less than "Size" as our largest piece of granularity.
 831     bool IsLittleEndian = MAI->isLittleEndian();
 832     for (unsigned Emitted = 0; Emitted != Size;) {
 833       unsigned Remaining = Size - Emitted;
 834       // The size of our partial emission must be a power of two less than
 835       // Size.
 836       unsigned EmissionSize = PowerOf2Floor(std::min(Remaining, Size - 1));
 837       // Calculate the byte offset of our partial emission taking into account
 838       // the endianness of the target.
 839       unsigned ByteOffset =
 840           IsLittleEndian ? Emitted : (Remaining - EmissionSize);
 841       uint64_t ValueToEmit = IntValue >> (ByteOffset * 8);
 842       // We truncate our partial emission to fit within the bounds of the
 843       // emission domain.  This produces nicer output and silences potential
 844       // truncation warnings when round tripping through another assembler.
 845       uint64_t Shift = 64 - EmissionSize * 8;
 846       assert(Shift < static_cast<uint64_t>(
 847                          std::numeric_limits<unsigned long long>::digits) &&
 848              "undefined behavior");
 849       ValueToEmit &= ~0ULL >> Shift;
 850       EmitIntValue(ValueToEmit, EmissionSize);
 851       Emitted += EmissionSize;
 852     }
 853     return;
 854   }
 855
 856   assert(Directive && "Invalid size for machine code value!");
 857   OS << Directive;
 858   Value->print(OS, MAI);
 859   EmitEOL();
 860 }
 861
 862 void MCAsmStreamer::EmitULEB128Value(const MCExpr *Value) {
 863   int64_t IntValue;
 864   if (Value->evaluateAsAbsolute(IntValue)) {
 865     EmitULEB128IntValue(IntValue);
 866     return;
 867   }
 868   OS << ".uleb128 ";
 869   Value->print(OS, MAI);
 870   EmitEOL();
 871 }
 872
 873 void MCAsmStreamer::EmitSLEB128Value(const MCExpr *Value) {
 874   int64_t IntValue;
 875   if (Value->evaluateAsAbsolute(IntValue)) {
 876     EmitSLEB128IntValue(IntValue);
 877     return;
 878   }
 879   OS << ".sleb128 ";
 880   Value->print(OS, MAI);
 881   EmitEOL();
 882 }
 883
 884 void MCAsmStreamer::EmitDTPRel64Value(const MCExpr *Value) {
 885   assert(MAI->getDTPRel64Directive() != nullptr);
 886   OS << MAI->getDTPRel64Directive();
 887   Value->print(OS, MAI);
 888   EmitEOL();
 889 }
 890
 891 void MCAsmStreamer::EmitDTPRel32Value(const MCExpr *Value) {
 892   assert(MAI->getDTPRel32Directive() != nullptr);
 893   OS << MAI->getDTPRel32Directive();
 894   Value->print(OS, MAI);
 895   EmitEOL();
 896 }
 897
 898 void MCAsmStreamer::EmitTPRel64Value(const MCExpr *Value) {
 899   assert(MAI->getTPRel64Directive() != nullptr);
 900   OS << MAI->getTPRel64Directive();
 901   Value->print(OS, MAI);
 902   EmitEOL();
 903 }
 904
 905 void MCAsmStreamer::EmitTPRel32Value(const MCExpr *Value) {
 906   assert(MAI->getTPRel32Directive() != nullptr);
 907   OS << MAI->getTPRel32Directive();
 908   Value->print(OS, MAI);
 909   EmitEOL();
 910 }
 911
 912 void MCAsmStreamer::EmitGPRel64Value(const MCExpr *Value) {
 913   assert(MAI->getGPRel64Directive() != nullptr);
 914   OS << MAI->getGPRel64Directive();
 915   Value->print(OS, MAI);
 916   EmitEOL();
 917 }
 918
 919 void MCAsmStreamer::EmitGPRel32Value(const MCExpr *Value) {
 920   assert(MAI->getGPRel32Directive() != nullptr);
 921   OS << MAI->getGPRel32Directive();
 922   Value->print(OS, MAI);
 923   EmitEOL();
 924 }
 925
 926 /// emitFill - Emit NumBytes bytes worth of the value specified by
 927 /// FillValue.  This implements directives such as '.space'.
 928 void MCAsmStreamer::emitFill(uint64_t NumBytes, uint8_t FillValue) {
 929   if (NumBytes == 0) return;
 930
 931   const MCExpr *E = MCConstantExpr::create(NumBytes, getContext());
 932   emitFill(*E, FillValue);
 933 }
 934
 935 void MCAsmStreamer::emitFill(const MCExpr &NumBytes, uint64_t FillValue,
 936                              SMLoc Loc) {
 937   if (const char *ZeroDirective = MAI->getZeroDirective()) {
 938     // FIXME: Emit location directives
 939     OS << ZeroDirective;
 940     NumBytes.print(OS, MAI);
 941     if (FillValue != 0)
 942       OS << ',' << (int)FillValue;
 943     EmitEOL();
 944     return;
 945   }
 946
 947   MCStreamer::emitFill(NumBytes, FillValue);
 948 }
 949
 950 void MCAsmStreamer::emitFill(uint64_t NumValues, int64_t Size, int64_t Expr) {
 951   if (NumValues == 0)
 952     return;
 953
 954   const MCExpr *E = MCConstantExpr::create(NumValues, getContext());
 955   emitFill(*E, Size, Expr);
 956 }
 957
 958 void MCAsmStreamer::emitFill(const MCExpr &NumValues, int64_t Size,
 959                              int64_t Expr, SMLoc Loc) {
 960   // FIXME: Emit location directives
 961   OS << "\t.fill\t";
 962   NumValues.print(OS, MAI);
 963   OS << ", " << Size << ", 0x";
 964   OS.write_hex(truncateToSize(Expr, 4));
 965   EmitEOL();
 966 }
 967
 968 void MCAsmStreamer::EmitValueToAlignment(unsigned ByteAlignment, int64_t Value,
 969                                          unsigned ValueSize,
 970                                          unsigned MaxBytesToEmit) {
 971   // Some assemblers don't support non-power of two alignments, so we always
 972   // emit alignments as a power of two if possible.
 973   if (isPowerOf2_32(ByteAlignment)) {
 974     switch (ValueSize) {
 975     default:
 976       llvm_unreachable("Invalid size for machine code value!");
 977     case 1:
 978       OS << "\t.p2align\t";
 979       break;
 980     case 2:
 981       OS << ".p2alignw ";
 982       break;
 983     case 4:
 984       OS << ".p2alignl ";
 985       break;
 986     case 8:
 987       llvm_unreachable("Unsupported alignment size!");
 988     }
 989
 990     OS << Log2_32(ByteAlignment);
 991
 992     if (Value || MaxBytesToEmit) {
 993       OS << ", 0x";
 994       OS.write_hex(truncateToSize(Value, ValueSize));
 995
 996       if (MaxBytesToEmit)
 997         OS << ", " << MaxBytesToEmit;
 998     }
 999     EmitEOL();
1000     return;
1001   }
1002
1003   // Non-power of two alignment.  This is not widely supported by assemblers.
1004   // FIXME: Parameterize this based on MAI.
1005   switch (ValueSize) {
1006   default: llvm_unreachable("Invalid size for machine code value!");
1007   case 1: OS << ".balign";  break;
1008   case 2: OS << ".balignw"; break;
1009   case 4: OS << ".balignl"; break;
1010   case 8: llvm_unreachable("Unsupported alignment size!");
1011   }
1012
1013   OS << ' ' << ByteAlignment;
1014   OS << ", " << truncateToSize(Value, ValueSize);
1015   if (MaxBytesToEmit)
1016     OS << ", " << MaxBytesToEmit;
1017   EmitEOL();
1018 }
1019
1020 void MCAsmStreamer::EmitCodeAlignment(unsigned ByteAlignment,
1021                                       unsigned MaxBytesToEmit) {
1022   // Emit with a text fill value.
1023   EmitValueToAlignment(ByteAlignment, MAI->getTextAlignFillValue(),
1024                        1, MaxBytesToEmit);
1025 }
1026
1027 void MCAsmStreamer::emitValueToOffset(const MCExpr *Offset,
1028                                       unsigned char Value,
1029                                       SMLoc Loc) {
1030   // FIXME: Verify that Offset is associated with the current section.
1031   OS << ".org ";
1032   Offset->print(OS, MAI);
1033   OS << ", " << (unsigned)Value;
1034   EmitEOL();
1035 }
1036
1037 void MCAsmStreamer::EmitFileDirective(StringRef Filename) {
1038   assert(MAI->hasSingleParameterDotFile());
1039   OS << "\t.file\t";
1040   PrintQuotedString(Filename, OS);
1041   EmitEOL();
1042 }
1043
1044 unsigned MCAsmStreamer::EmitDwarfFileDirective(unsigned FileNo,
1045                                                StringRef Directory,
1046                                                StringRef Filename,
1047                                                unsigned CUID) {
1048   assert(CUID == 0);
1049
1050   MCDwarfLineTable &Table = getContext().getMCDwarfLineTable(CUID);
1051   unsigned NumFiles = Table.getMCDwarfFiles().size();
1052   FileNo = Table.getFile(Directory, Filename, FileNo);
1053   if (FileNo == 0)
1054     return 0;
1055   if (NumFiles == Table.getMCDwarfFiles().size())
1056     return FileNo;
1057
1058   SmallString<128> FullPathName;
1059
1060   if (!UseDwarfDirectory && !Directory.empty()) {
1061     if (sys::path::is_absolute(Filename))
1062       Directory = "";
1063     else {
1064       FullPathName = Directory;
1065       sys::path::append(FullPathName, Filename);
1066       Directory = "";
1067       Filename = FullPathName;
1068     }
1069   }
1070
1071   OS << "\t.file\t" << FileNo << ' ';
1072   if (!Directory.empty()) {
1073     PrintQuotedString(Directory, OS);
1074     OS << ' ';
1075   }
1076   PrintQuotedString(Filename, OS);
1077   EmitEOL();
1078
1079   return FileNo;
1080 }
1081
1082 void MCAsmStreamer::EmitDwarfLocDirective(unsigned FileNo, unsigned Line,
1083                                           unsigned Column, unsigned Flags,
1084                                           unsigned Isa,
1085                                           unsigned Discriminator,
1086                                           StringRef FileName) {
1087   OS << "\t.loc\t" << FileNo << " " << Line << " " << Column;
1088   if (Flags & DWARF2_FLAG_BASIC_BLOCK)
1089     OS << " basic_block";
1090   if (Flags & DWARF2_FLAG_PROLOGUE_END)
1091     OS << " prologue_end";
1092   if (Flags & DWARF2_FLAG_EPILOGUE_BEGIN)
1093     OS << " epilogue_begin";
1094
1095   unsigned OldFlags = getContext().getCurrentDwarfLoc().getFlags();
1096   if ((Flags & DWARF2_FLAG_IS_STMT) != (OldFlags & DWARF2_FLAG_IS_STMT)) {
1097     OS << " is_stmt ";
1098
1099     if (Flags & DWARF2_FLAG_IS_STMT)
1100       OS << "1";
1101     else
1102       OS << "0";
1103   }
1104
1105   if (Isa)
1106     OS << " isa " << Isa;
1107   if (Discriminator)
1108     OS << " discriminator " << Discriminator;
1109
1110   if (IsVerboseAsm) {
1111     OS.PadToColumn(MAI->getCommentColumn());
1112     OS << MAI->getCommentString() << ' ' << FileName << ':'
1113        << Line << ':' << Column;
1114   }
1115   EmitEOL();
1116   this->MCStreamer::EmitDwarfLocDirective(FileNo, Line, Column, Flags,
1117                                           Isa, Discriminator, FileName);
1118 }
1119
1120 MCSymbol *MCAsmStreamer::getDwarfLineTableSymbol(unsigned CUID) {
1121   // Always use the zeroth line table, since asm syntax only supports one line
1122   // table for now.
1123   return MCStreamer::getDwarfLineTableSymbol(0);
1124 }
1125
1126 bool MCAsmStreamer::EmitCVFileDirective(unsigned FileNo, StringRef Filename,
1127                                         ArrayRef<uint8_t> Checksum,
1128                                         unsigned ChecksumKind) {
1129   if (!getContext().getCVContext().addFile(*this, FileNo, Filename, Checksum,
1130                                            ChecksumKind))
1131     return false;
1132
1133   OS << "\t.cv_file\t" << FileNo << ' ';
1134   PrintQuotedString(Filename, OS);
1135
1136   if (!ChecksumKind) {
1137     EmitEOL();
1138     return true;
1139   }
1140
1141   OS << ' ';
1142   PrintQuotedString(toHex(Checksum), OS);
1143   OS << ' ' << ChecksumKind;
1144
1145   EmitEOL();
1146   return true;
1147 }
1148
1149 bool MCAsmStreamer::EmitCVFuncIdDirective(unsigned FuncId) {
1150   OS << "\t.cv_func_id " << FuncId << '\n';
1151   return MCStreamer::EmitCVFuncIdDirective(FuncId);
1152 }
1153
1154 bool MCAsmStreamer::EmitCVInlineSiteIdDirective(unsigned FunctionId,
1155                                                 unsigned IAFunc,
1156                                                 unsigned IAFile,
1157                                                 unsigned IALine, unsigned IACol,
1158                                                 SMLoc Loc) {
1159   OS << "\t.cv_inline_site_id " << FunctionId << " within " << IAFunc
1160      << " inlined_at " << IAFile << ' ' << IALine << ' ' << IACol << '\n';
1161   return MCStreamer::EmitCVInlineSiteIdDirective(FunctionId, IAFunc, IAFile,
1162                                                  IALine, IACol, Loc);
1163 }
1164
1165 void MCAsmStreamer::EmitCVLocDirective(unsigned FunctionId, unsigned FileNo,
1166                                        unsigned Line, unsigned Column,
1167                                        bool PrologueEnd, bool IsStmt,
1168                                        StringRef FileName, SMLoc Loc) {
1169   OS << "\t.cv_loc\t" << FunctionId << " " << FileNo << " " << Line << " "
1170      << Column;
1171   if (PrologueEnd)
1172     OS << " prologue_end";
1173
1174   unsigned OldIsStmt = getContext().getCVContext().getCurrentCVLoc().isStmt();
1175   if (IsStmt != OldIsStmt) {
1176     OS << " is_stmt ";
1177
1178     if (IsStmt)
1179       OS << "1";
1180     else
1181       OS << "0";
1182   }
1183
1184   if (IsVerboseAsm) {
1185     OS.PadToColumn(MAI->getCommentColumn());
1186     OS << MAI->getCommentString() << ' ' << FileName << ':' << Line << ':'
1187        << Column;
1188   }
1189   EmitEOL();
1190   this->MCStreamer::EmitCVLocDirective(FunctionId, FileNo, Line, Column,
1191                                        PrologueEnd, IsStmt, FileName, Loc);
1192 }
1193
1194 void MCAsmStreamer::EmitCVLinetableDirective(unsigned FunctionId,
1195                                              const MCSymbol *FnStart,
1196                                              const MCSymbol *FnEnd) {
1197   OS << "\t.cv_linetable\t" << FunctionId << ", ";
1198   FnStart->print(OS, MAI);
1199   OS << ", ";
1200   FnEnd->print(OS, MAI);
1201   EmitEOL();
1202   this->MCStreamer::EmitCVLinetableDirective(FunctionId, FnStart, FnEnd);
1203 }
1204
1205 void MCAsmStreamer::EmitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
1206                                                    unsigned SourceFileId,
1207                                                    unsigned SourceLineNum,
1208                                                    const MCSymbol *FnStartSym,
1209                                                    const MCSymbol *FnEndSym) {
1210   OS << "\t.cv_inline_linetable\t" << PrimaryFunctionId << ' ' << SourceFileId
1211      << ' ' << SourceLineNum << ' ';
1212   FnStartSym->print(OS, MAI);
1213   OS << ' ';
1214   FnEndSym->print(OS, MAI);
1215   EmitEOL();
1216   this->MCStreamer::EmitCVInlineLinetableDirective(
1217       PrimaryFunctionId, SourceFileId, SourceLineNum, FnStartSym, FnEndSym);
1218 }
1219
1220 void MCAsmStreamer::EmitCVDefRangeDirective(
1221     ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
1222     StringRef FixedSizePortion) {
1223   OS << "\t.cv_def_range\t";
1224   for (std::pair<const MCSymbol *, const MCSymbol *> Range : Ranges) {
1225     OS << ' ';
1226     Range.first->print(OS, MAI);
1227     OS << ' ';
1228     Range.second->print(OS, MAI);
1229   }
1230   OS << ", ";
1231   PrintQuotedString(FixedSizePortion, OS);
1232   EmitEOL();
1233   this->MCStreamer::EmitCVDefRangeDirective(Ranges, FixedSizePortion);
1234 }
1235
1236 void MCAsmStreamer::EmitCVStringTableDirective() {
1237   OS << "\t.cv_stringtable";
1238   EmitEOL();
1239 }
1240
1241 void MCAsmStreamer::EmitCVFileChecksumsDirective() {
1242   OS << "\t.cv_filechecksums";
1243   EmitEOL();
1244 }
1245
1246 void MCAsmStreamer::EmitCVFileChecksumOffsetDirective(unsigned FileNo) {
1247   OS << "\t.cv_filechecksumoffset\t" << FileNo;
1248   EmitEOL();
1249 }
1250
1251 void MCAsmStreamer::EmitIdent(StringRef IdentString) {
1252   assert(MAI->hasIdentDirective() && ".ident directive not supported");
1253   OS << "\t.ident\t";
1254   PrintQuotedString(IdentString, OS);
1255   EmitEOL();
1256 }
1257
1258 void MCAsmStreamer::EmitCFISections(bool EH, bool Debug) {
1259   MCStreamer::EmitCFISections(EH, Debug);
1260   OS << "\t.cfi_sections ";
1261   if (EH) {
1262     OS << ".eh_frame";
1263     if (Debug)
1264       OS << ", .debug_frame";
1265   } else if (Debug) {
1266     OS << ".debug_frame";
1267   }
1268
1269   EmitEOL();
1270 }
1271
1272 void MCAsmStreamer::EmitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
1273   OS << "\t.cfi_startproc";
1274   if (Frame.IsSimple)
1275     OS << " simple";
1276   EmitEOL();
1277 }
1278
1279 void MCAsmStreamer::EmitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
1280   MCStreamer::EmitCFIEndProcImpl(Frame);
1281   OS << "\t.cfi_endproc";
1282   EmitEOL();
1283 }
1284
1285 void MCAsmStreamer::EmitRegisterName(int64_t Register) {
1286   if (!MAI->useDwarfRegNumForCFI()) {
1287     const MCRegisterInfo *MRI = getContext().getRegisterInfo();
1288     unsigned LLVMRegister = MRI->getLLVMRegNum(Register, true);
1289     InstPrinter->printRegName(OS, LLVMRegister);
1290   } else {
1291     OS << Register;
1292   }
1293 }
1294
1295 void MCAsmStreamer::EmitCFIDefCfa(int64_t Register, int64_t Offset) {
1296   MCStreamer::EmitCFIDefCfa(Register, Offset);
1297   OS << "\t.cfi_def_cfa ";
1298   EmitRegisterName(Register);
1299   OS << ", " << Offset;
1300   EmitEOL();
1301 }
1302
1303 void MCAsmStreamer::EmitCFIDefCfaOffset(int64_t Offset) {
1304   MCStreamer::EmitCFIDefCfaOffset(Offset);
1305   OS << "\t.cfi_def_cfa_offset " << Offset;
1306   EmitEOL();
1307 }
1308
1309 static void PrintCFIEscape(llvm::formatted_raw_ostream &OS, StringRef Values) {
1310   OS << "\t.cfi_escape ";
1311   if (!Values.empty()) {
1312     size_t e = Values.size() - 1;
1313     for (size_t i = 0; i < e; ++i)
1314       OS << format("0x%02x", uint8_t(Values[i])) << ", ";
1315     OS << format("0x%02x", uint8_t(Values[e]));
1316   }
1317 }
1318
1319 void MCAsmStreamer::EmitCFIEscape(StringRef Values) {
1320   MCStreamer::EmitCFIEscape(Values);
1321   PrintCFIEscape(OS, Values);
1322   EmitEOL();
1323 }
1324
1325 void MCAsmStreamer::EmitCFIGnuArgsSize(int64_t Size) {
1326   MCStreamer::EmitCFIGnuArgsSize(Size);
1327
1328   uint8_t Buffer[16] = { dwarf::DW_CFA_GNU_args_size };
1329   unsigned Len = encodeULEB128(Size, Buffer + 1) + 1;
1330
1331   PrintCFIEscape(OS, StringRef((const char *)&Buffer[0], Len));
1332   EmitEOL();
1333 }
1334
1335 void MCAsmStreamer::EmitCFIDefCfaRegister(int64_t Register) {
1336   MCStreamer::EmitCFIDefCfaRegister(Register);
1337   OS << "\t.cfi_def_cfa_register ";
1338   EmitRegisterName(Register);
1339   EmitEOL();
1340 }
1341
1342 void MCAsmStreamer::EmitCFIOffset(int64_t Register, int64_t Offset) {
1343   this->MCStreamer::EmitCFIOffset(Register, Offset);
1344   OS << "\t.cfi_offset ";
1345   EmitRegisterName(Register);
1346   OS << ", " << Offset;
1347   EmitEOL();
1348 }
1349
1350 void MCAsmStreamer::EmitCFIPersonality(const MCSymbol *Sym,
1351                                        unsigned Encoding) {
1352   MCStreamer::EmitCFIPersonality(Sym, Encoding);
1353   OS << "\t.cfi_personality " << Encoding << ", ";
1354   Sym->print(OS, MAI);
1355   EmitEOL();
1356 }
1357
1358 void MCAsmStreamer::EmitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
1359   MCStreamer::EmitCFILsda(Sym, Encoding);
1360   OS << "\t.cfi_lsda " << Encoding << ", ";
1361   Sym->print(OS, MAI);
1362   EmitEOL();
1363 }
1364
1365 void MCAsmStreamer::EmitCFIRememberState() {
1366   MCStreamer::EmitCFIRememberState();
1367   OS << "\t.cfi_remember_state";
1368   EmitEOL();
1369 }
1370
1371 void MCAsmStreamer::EmitCFIRestoreState() {
1372   MCStreamer::EmitCFIRestoreState();
1373   OS << "\t.cfi_restore_state";
1374   EmitEOL();
1375 }
1376
1377 void MCAsmStreamer::EmitCFISameValue(int64_t Register) {
1378   MCStreamer::EmitCFISameValue(Register);
1379   OS << "\t.cfi_same_value ";
1380   EmitRegisterName(Register);
1381   EmitEOL();
1382 }
1383
1384 void MCAsmStreamer::EmitCFIRelOffset(int64_t Register, int64_t Offset) {
1385   MCStreamer::EmitCFIRelOffset(Register, Offset);
1386   OS << "\t.cfi_rel_offset ";
1387   EmitRegisterName(Register);
1388   OS << ", " << Offset;
1389   EmitEOL();
1390 }
1391
1392 void MCAsmStreamer::EmitCFIAdjustCfaOffset(int64_t Adjustment) {
1393   MCStreamer::EmitCFIAdjustCfaOffset(Adjustment);
1394   OS << "\t.cfi_adjust_cfa_offset " << Adjustment;
1395   EmitEOL();
1396 }
1397
1398 void MCAsmStreamer::EmitCFISignalFrame() {
1399   MCStreamer::EmitCFISignalFrame();
1400   OS << "\t.cfi_signal_frame";
1401   EmitEOL();
1402 }
1403
1404 void MCAsmStreamer::EmitCFIUndefined(int64_t Register) {
1405   MCStreamer::EmitCFIUndefined(Register);
1406   OS << "\t.cfi_undefined " << Register;
1407   EmitEOL();
1408 }
1409
1410 void MCAsmStreamer::EmitCFIRegister(int64_t Register1, int64_t Register2) {
1411   MCStreamer::EmitCFIRegister(Register1, Register2);
1412   OS << "\t.cfi_register " << Register1 << ", " << Register2;
1413   EmitEOL();
1414 }
1415
1416 void MCAsmStreamer::EmitCFIWindowSave() {
1417   MCStreamer::EmitCFIWindowSave();
1418   OS << "\t.cfi_window_save";
1419   EmitEOL();
1420 }
1421
1422 void MCAsmStreamer::EmitCFIReturnColumn(int64_t Register) {
1423   MCStreamer::EmitCFIReturnColumn(Register);
1424   OS << "\t.cfi_return_column " << Register;
1425   EmitEOL();
1426 }
1427
1428 void MCAsmStreamer::EmitWinCFIStartProc(const MCSymbol *Symbol) {
1429   MCStreamer::EmitWinCFIStartProc(Symbol);
1430
1431   OS << ".seh_proc ";
1432   Symbol->print(OS, MAI);
1433   EmitEOL();
1434 }
1435
1436 void MCAsmStreamer::EmitWinCFIEndProc() {
1437   MCStreamer::EmitWinCFIEndProc();
1438
1439   OS << "\t.seh_endproc";
1440   EmitEOL();
1441 }
1442
1443 void MCAsmStreamer::EmitWinCFIStartChained() {
1444   MCStreamer::EmitWinCFIStartChained();
1445
1446   OS << "\t.seh_startchained";
1447   EmitEOL();
1448 }
1449
1450 void MCAsmStreamer::EmitWinCFIEndChained() {
1451   MCStreamer::EmitWinCFIEndChained();
1452
1453   OS << "\t.seh_endchained";
1454   EmitEOL();
1455 }
1456
1457 void MCAsmStreamer::EmitWinEHHandler(const MCSymbol *Sym, bool Unwind,
1458                                       bool Except) {
1459   MCStreamer::EmitWinEHHandler(Sym, Unwind, Except);
1460
1461   OS << "\t.seh_handler ";
1462   Sym->print(OS, MAI);
1463   if (Unwind)
1464     OS << ", @unwind";
1465   if (Except)
1466     OS << ", @except";
1467   EmitEOL();
1468 }
1469
1470 void MCAsmStreamer::EmitWinEHHandlerData() {
1471   MCStreamer::EmitWinEHHandlerData();
1472
1473   // Switch sections. Don't call SwitchSection directly, because that will
1474   // cause the section switch to be visible in the emitted assembly.
1475   // We only do this so the section switch that terminates the handler
1476   // data block is visible.
1477   WinEH::FrameInfo *CurFrame = getCurrentWinFrameInfo();
1478   MCSection *TextSec = &CurFrame->Function->getSection();
1479   MCSection *XData = getAssociatedXDataSection(TextSec);
1480   SwitchSectionNoChange(XData);
1481
1482   OS << "\t.seh_handlerdata";
1483   EmitEOL();
1484 }
1485
1486 void MCAsmStreamer::EmitWinCFIPushReg(unsigned Register) {
1487   MCStreamer::EmitWinCFIPushReg(Register);
1488
1489   OS << "\t.seh_pushreg " << Register;
1490   EmitEOL();
1491 }
1492
1493 void MCAsmStreamer::EmitWinCFISetFrame(unsigned Register, unsigned Offset) {
1494   MCStreamer::EmitWinCFISetFrame(Register, Offset);
1495
1496   OS << "\t.seh_setframe " << Register << ", " << Offset;
1497   EmitEOL();
1498 }
1499
1500 void MCAsmStreamer::EmitWinCFIAllocStack(unsigned Size) {
1501   MCStreamer::EmitWinCFIAllocStack(Size);
1502
1503   OS << "\t.seh_stackalloc " << Size;
1504   EmitEOL();
1505 }
1506
1507 void MCAsmStreamer::EmitWinCFISaveReg(unsigned Register, unsigned Offset) {
1508   MCStreamer::EmitWinCFISaveReg(Register, Offset);
1509
1510   OS << "\t.seh_savereg " << Register << ", " << Offset;
1511   EmitEOL();
1512 }
1513
1514 void MCAsmStreamer::EmitWinCFISaveXMM(unsigned Register, unsigned Offset) {
1515   MCStreamer::EmitWinCFISaveXMM(Register, Offset);
1516
1517   OS << "\t.seh_savexmm " << Register << ", " << Offset;
1518   EmitEOL();
1519 }
1520
1521 void MCAsmStreamer::EmitWinCFIPushFrame(bool Code) {
1522   MCStreamer::EmitWinCFIPushFrame(Code);
1523
1524   OS << "\t.seh_pushframe";
1525   if (Code)
1526     OS << " @code";
1527   EmitEOL();
1528 }
1529
1530 void MCAsmStreamer::EmitWinCFIEndProlog() {
1531   MCStreamer::EmitWinCFIEndProlog();
1532
1533   OS << "\t.seh_endprologue";
1534   EmitEOL();
1535 }
1536
1537 void MCAsmStreamer::AddEncodingComment(const MCInst &Inst,
1538                                        const MCSubtargetInfo &STI,
1539                                        bool PrintSchedInfo) {
1540   raw_ostream &OS = GetCommentOS();
1541   SmallString<256> Code;
1542   SmallVector<MCFixup, 4> Fixups;
1543   raw_svector_ostream VecOS(Code);
1544   Emitter->encodeInstruction(Inst, VecOS, Fixups, STI);
1545
1546   // If we are showing fixups, create symbolic markers in the encoded
1547   // representation. We do this by making a per-bit map to the fixup item index,
1548   // then trying to display it as nicely as possible.
1549   SmallVector<uint8_t, 64> FixupMap;
1550   FixupMap.resize(Code.size() * 8);
1551   for (unsigned i = 0, e = Code.size() * 8; i != e; ++i)
1552     FixupMap[i] = 0;
1553
1554   for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
1555     MCFixup &F = Fixups[i];
1556     const MCFixupKindInfo &Info = AsmBackend->getFixupKindInfo(F.getKind());
1557     for (unsigned j = 0; j != Info.TargetSize; ++j) {
1558       unsigned Index = F.getOffset() * 8 + Info.TargetOffset + j;
1559       assert(Index < Code.size() * 8 && "Invalid offset in fixup!");
1560       FixupMap[Index] = 1 + i;
1561     }
1562   }
1563
1564   // FIXME: Note the fixup comments for Thumb2 are completely bogus since the
1565   // high order halfword of a 32-bit Thumb2 instruction is emitted first.
1566   OS << "encoding: [";
1567   for (unsigned i = 0, e = Code.size(); i != e; ++i) {
1568     if (i)
1569       OS << ',';
1570
1571     // See if all bits are the same map entry.
1572     uint8_t MapEntry = FixupMap[i * 8 + 0];
1573     for (unsigned j = 1; j != 8; ++j) {
1574       if (FixupMap[i * 8 + j] == MapEntry)
1575         continue;
1576
1577       MapEntry = uint8_t(~0U);
1578       break;
1579     }
1580
1581     if (MapEntry != uint8_t(~0U)) {
1582       if (MapEntry == 0) {
1583         OS << format("0x%02x", uint8_t(Code[i]));
1584       } else {
1585         if (Code[i]) {
1586           // FIXME: Some of the 8 bits require fix up.
1587           OS << format("0x%02x", uint8_t(Code[i])) << '\''
1588              << char('A' + MapEntry - 1) << '\'';
1589         } else
1590           OS << char('A' + MapEntry - 1);
1591       }
1592     } else {
1593       // Otherwise, write out in binary.
1594       OS << "0b";
1595       for (unsigned j = 8; j--;) {
1596         unsigned Bit = (Code[i] >> j) & 1;
1597
1598         unsigned FixupBit;
1599         if (MAI->isLittleEndian())
1600           FixupBit = i * 8 + j;
1601         else
1602           FixupBit = i * 8 + (7-j);
1603
1604         if (uint8_t MapEntry = FixupMap[FixupBit]) {
1605           assert(Bit == 0 && "Encoder wrote into fixed up bit!");
1606           OS << char('A' + MapEntry - 1);
1607         } else
1608           OS << Bit;
1609       }
1610     }
1611   }
1612   OS << "]";
1613   // If we are not going to add fixup or schedule comments after this point
1614   // then we have to end the current comment line with "\n".
1615   if (Fixups.size() || !PrintSchedInfo)
1616     OS << "\n";
1617
1618   for (unsigned i = 0, e = Fixups.size(); i != e; ++i) {
1619     MCFixup &F = Fixups[i];
1620     const MCFixupKindInfo &Info = AsmBackend->getFixupKindInfo(F.getKind());
1621     OS << "  fixup " << char('A' + i) << " - " << "offset: " << F.getOffset()
1622        << ", value: " << *F.getValue() << ", kind: " << Info.Name << "\n";
1623   }
1624 }
1625
1626 void MCAsmStreamer::EmitInstruction(const MCInst &Inst,
1627                                     const MCSubtargetInfo &STI,
1628                                     bool PrintSchedInfo) {
1629   assert(getCurrentSectionOnly() &&
1630          "Cannot emit contents before setting section!");
1631
1632   // Show the encoding in a comment if we have a code emitter.
1633   if (Emitter)
1634     AddEncodingComment(Inst, STI, PrintSchedInfo);
1635
1636   // Show the MCInst if enabled.
1637   if (ShowInst) {
1638     if (PrintSchedInfo)
1639       GetCommentOS() << "\n";
1640     Inst.dump_pretty(GetCommentOS(), InstPrinter.get(), "\n ");
1641     GetCommentOS() << "\n";
1642   }
1643
1644   if(getTargetStreamer())
1645     getTargetStreamer()->prettyPrintAsm(*InstPrinter, OS, Inst, STI);
1646   else
1647     InstPrinter->printInst(&Inst, OS, "", STI);
1648
1649   if (PrintSchedInfo) {
1650     std::string SI = STI.getSchedInfoStr(Inst);
1651     if (!SI.empty())
1652       GetCommentOS() << SI;
1653   }
1654
1655   StringRef Comments = CommentToEmit;
1656   if (Comments.size() && Comments.back() != '\n')
1657     GetCommentOS() << "\n";
1658
1659   EmitEOL();
1660 }
1661
1662 void MCAsmStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
1663   OS << "\t.bundle_align_mode " << AlignPow2;
1664   EmitEOL();
1665 }
1666
1667 void MCAsmStreamer::EmitBundleLock(bool AlignToEnd) {
1668   OS << "\t.bundle_lock";
1669   if (AlignToEnd)
1670     OS << " align_to_end";
1671   EmitEOL();
1672 }
1673
1674 void MCAsmStreamer::EmitBundleUnlock() {
1675   OS << "\t.bundle_unlock";
1676   EmitEOL();
1677 }
1678
1679 bool MCAsmStreamer::EmitRelocDirective(const MCExpr &Offset, StringRef Name,
1680                                        const MCExpr *Expr, SMLoc) {
1681   OS << "\t.reloc ";
1682   Offset.print(OS, MAI);
1683   OS << ", " << Name;
1684   if (Expr) {
1685     OS << ", ";
1686     Expr->print(OS, MAI);
1687   }
1688   EmitEOL();
1689   return false;
1690 }
1691
1692 /// EmitRawText - If this file is backed by an assembly streamer, this dumps
1693 /// the specified string in the output .s file.  This capability is
1694 /// indicated by the hasRawTextSupport() predicate.
1695 void MCAsmStreamer::EmitRawTextImpl(StringRef String) {
1696   if (!String.empty() && String.back() == '\n')
1697     String = String.substr(0, String.size()-1);
1698   OS << String;
1699   EmitEOL();
1700 }
1701
1702 void MCAsmStreamer::FinishImpl() {
1703   // If we are generating dwarf for assembly source files dump out the sections.
1704   if (getContext().getGenDwarfForAssembly())
1705     MCGenDwarfInfo::Emit(this);
1706
1707   // Emit the label for the line table, if requested - since the rest of the
1708   // line table will be defined by .loc/.file directives, and not emitted
1709   // directly, the label is the only work required here.
1710   auto &Tables = getContext().getMCDwarfLineTables();
1711   if (!Tables.empty()) {
1712     assert(Tables.size() == 1 && "asm output only supports one line table");
1713     if (auto *Label = Tables.begin()->second.getLabel()) {
1714       SwitchSection(getContext().getObjectFileInfo()->getDwarfLineSection());
1715       EmitLabel(Label);
1716     }
1717   }
1718 }
1719
1720 MCStreamer *llvm::createAsmStreamer(MCContext &Context,
1721                                     std::unique_ptr<formatted_raw_ostream> OS,
1722                                     bool isVerboseAsm, bool useDwarfDirectory,
1723                                     MCInstPrinter *IP, MCCodeEmitter *CE,
1724                                     MCAsmBackend *MAB, bool ShowInst) {
1725   return new MCAsmStreamer(Context, std::move(OS), isVerboseAsm,
1726                            useDwarfDirectory, IP, CE, MAB, ShowInst);
1727 }