llvm/lib/MC/MCStreamer.cpp

   1 //===- lib/MC/MCStreamer.cpp - Streaming Machine Code Output --------------===//
   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 #include "llvm/MC/MCStreamer.h"
  10 #include "llvm/ADT/SmallString.h"
  11 #include "llvm/ADT/StringRef.h"
  12 #include "llvm/ADT/Twine.h"
  13 #include "llvm/BinaryFormat/COFF.h"
  14 #include "llvm/BinaryFormat/MachO.h"
  15 #include "llvm/DebugInfo/CodeView/SymbolRecord.h"
  16 #include "llvm/MC/MCAsmBackend.h"
  17 #include "llvm/MC/MCAsmInfo.h"
  18 #include "llvm/MC/MCCodeView.h"
  19 #include "llvm/MC/MCContext.h"
  20 #include "llvm/MC/MCDwarf.h"
  21 #include "llvm/MC/MCExpr.h"
  22 #include "llvm/MC/MCInst.h"
  23 #include "llvm/MC/MCInstPrinter.h"
  24 #include "llvm/MC/MCObjectFileInfo.h"
  25 #include "llvm/MC/MCPseudoProbe.h"
  26 #include "llvm/MC/MCRegister.h"
  27 #include "llvm/MC/MCRegisterInfo.h"
  28 #include "llvm/MC/MCSection.h"
  29 #include "llvm/MC/MCSectionCOFF.h"
  30 #include "llvm/MC/MCSymbol.h"
  31 #include "llvm/MC/MCWin64EH.h"
  32 #include "llvm/MC/MCWinEH.h"
  33 #include "llvm/Support/Casting.h"
  34 #include "llvm/Support/ErrorHandling.h"
  35 #include "llvm/Support/LEB128.h"
  36 #include "llvm/Support/MathExtras.h"
  37 #include "llvm/Support/raw_ostream.h"
  38 #include <cassert>
  39 #include <cstdint>
  40 #include <cstdlib>
  41 #include <optional>
  42 #include <utility>
  43
  44 using namespace llvm;
  45
  46 MCTargetStreamer::MCTargetStreamer(MCStreamer &S) : Streamer(S) {
  47   S.setTargetStreamer(this);
  48 }
  49
  50 // Pin the vtables to this file.
  51 MCTargetStreamer::~MCTargetStreamer() = default;
  52
  53 void MCTargetStreamer::emitLabel(MCSymbol *Symbol) {}
  54
  55 void MCTargetStreamer::finish() {}
  56
  57 void MCTargetStreamer::emitConstantPools() {}
  58
  59 void MCTargetStreamer::changeSection(const MCSection *CurSection,
  60                                      MCSection *Section, uint32_t Subsection,
  61                                      raw_ostream &OS) {
  62   Section->printSwitchToSection(*Streamer.getContext().getAsmInfo(),
  63                                 Streamer.getContext().getTargetTriple(), OS,
  64                                 Subsection);
  65 }
  66
  67 void MCTargetStreamer::emitDwarfFileDirective(StringRef Directive) {
  68   Streamer.emitRawText(Directive);
  69 }
  70
  71 void MCTargetStreamer::emitValue(const MCExpr *Value) {
  72   SmallString<128> Str;
  73   raw_svector_ostream OS(Str);
  74
  75   Value->print(OS, Streamer.getContext().getAsmInfo());
  76   Streamer.emitRawText(OS.str());
  77 }
  78
  79 void MCTargetStreamer::emitRawBytes(StringRef Data) {
  80   const MCAsmInfo *MAI = Streamer.getContext().getAsmInfo();
  81   const char *Directive = MAI->getData8bitsDirective();
  82   for (const unsigned char C : Data.bytes()) {
  83     SmallString<128> Str;
  84     raw_svector_ostream OS(Str);
  85
  86     OS << Directive << (unsigned)C;
  87     Streamer.emitRawText(OS.str());
  88   }
  89 }
  90
  91 void MCTargetStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {}
  92
  93 MCStreamer::MCStreamer(MCContext &Ctx)
  94     : Context(Ctx), CurrentWinFrameInfo(nullptr),
  95       CurrentProcWinFrameInfoStartIndex(0) {
  96   SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
  97 }
  98
  99 MCStreamer::~MCStreamer() = default;
 100
 101 void MCStreamer::reset() {
 102   DwarfFrameInfos.clear();
 103   CurrentWinFrameInfo = nullptr;
 104   WinFrameInfos.clear();
 105   SectionStack.clear();
 106   SectionStack.push_back(std::pair<MCSectionSubPair, MCSectionSubPair>());
 107   CurFrag = nullptr;
 108 }
 109
 110 raw_ostream &MCStreamer::getCommentOS() {
 111   // By default, discard comments.
 112   return nulls();
 113 }
 114
 115 unsigned MCStreamer::getNumFrameInfos() { return DwarfFrameInfos.size(); }
 116 ArrayRef<MCDwarfFrameInfo> MCStreamer::getDwarfFrameInfos() const {
 117   return DwarfFrameInfos;
 118 }
 119
 120 void MCStreamer::emitRawComment(const Twine &T, bool TabPrefix) {}
 121
 122 void MCStreamer::addExplicitComment(const Twine &T) {}
 123 void MCStreamer::emitExplicitComments() {}
 124
 125 void MCStreamer::generateCompactUnwindEncodings(MCAsmBackend *MAB) {
 126   for (auto &FI : DwarfFrameInfos)
 127     FI.CompactUnwindEncoding =
 128         (MAB ? MAB->generateCompactUnwindEncoding(&FI, &Context) : 0);
 129 }
 130
 131 /// EmitIntValue - Special case of EmitValue that avoids the client having to
 132 /// pass in a MCExpr for constant integers.
 133 void MCStreamer::emitIntValue(uint64_t Value, unsigned Size) {
 134   assert(1 <= Size && Size <= 8 && "Invalid size");
 135   assert((isUIntN(8 * Size, Value) || isIntN(8 * Size, Value)) &&
 136          "Invalid size");
 137   const bool IsLittleEndian = Context.getAsmInfo()->isLittleEndian();
 138   uint64_t Swapped = support::endian::byte_swap(
 139       Value, IsLittleEndian ? llvm::endianness::little : llvm::endianness::big);
 140   unsigned Index = IsLittleEndian ? 0 : 8 - Size;
 141   emitBytes(StringRef(reinterpret_cast<char *>(&Swapped) + Index, Size));
 142 }
 143 void MCStreamer::emitIntValue(const APInt &Value) {
 144   if (Value.getNumWords() == 1) {
 145     emitIntValue(Value.getLimitedValue(), Value.getBitWidth() / 8);
 146     return;
 147   }
 148
 149   const bool IsLittleEndianTarget = Context.getAsmInfo()->isLittleEndian();
 150   const bool ShouldSwap = sys::IsLittleEndianHost != IsLittleEndianTarget;
 151   const APInt Swapped = ShouldSwap ? Value.byteSwap() : Value;
 152   const unsigned Size = Value.getBitWidth() / 8;
 153   SmallString<10> Tmp;
 154   Tmp.resize(Size);
 155   StoreIntToMemory(Swapped, reinterpret_cast<uint8_t *>(Tmp.data()), Size);
 156   emitBytes(Tmp.str());
 157 }
 158
 159 /// EmitULEB128IntValue - Special case of EmitULEB128Value that avoids the
 160 /// client having to pass in a MCExpr for constant integers.
 161 unsigned MCStreamer::emitULEB128IntValue(uint64_t Value, unsigned PadTo) {
 162   SmallString<128> Tmp;
 163   raw_svector_ostream OSE(Tmp);
 164   encodeULEB128(Value, OSE, PadTo);
 165   emitBytes(OSE.str());
 166   return Tmp.size();
 167 }
 168
 169 /// EmitSLEB128IntValue - Special case of EmitSLEB128Value that avoids the
 170 /// client having to pass in a MCExpr for constant integers.
 171 unsigned MCStreamer::emitSLEB128IntValue(int64_t Value) {
 172   SmallString<128> Tmp;
 173   raw_svector_ostream OSE(Tmp);
 174   encodeSLEB128(Value, OSE);
 175   emitBytes(OSE.str());
 176   return Tmp.size();
 177 }
 178
 179 void MCStreamer::emitValue(const MCExpr *Value, unsigned Size, SMLoc Loc) {
 180   emitValueImpl(Value, Size, Loc);
 181 }
 182
 183 void MCStreamer::emitSymbolValue(const MCSymbol *Sym, unsigned Size,
 184                                  bool IsSectionRelative) {
 185   assert((!IsSectionRelative || Size == 4) &&
 186          "SectionRelative value requires 4-bytes");
 187
 188   if (!IsSectionRelative)
 189     emitValueImpl(MCSymbolRefExpr::create(Sym, getContext()), Size);
 190   else
 191     emitCOFFSecRel32(Sym, /*Offset=*/0);
 192 }
 193
 194 void MCStreamer::emitDTPRel64Value(const MCExpr *Value) {
 195   report_fatal_error("unsupported directive in streamer");
 196 }
 197
 198 void MCStreamer::emitDTPRel32Value(const MCExpr *Value) {
 199   report_fatal_error("unsupported directive in streamer");
 200 }
 201
 202 void MCStreamer::emitTPRel64Value(const MCExpr *Value) {
 203   report_fatal_error("unsupported directive in streamer");
 204 }
 205
 206 void MCStreamer::emitTPRel32Value(const MCExpr *Value) {
 207   report_fatal_error("unsupported directive in streamer");
 208 }
 209
 210 void MCStreamer::emitGPRel64Value(const MCExpr *Value) {
 211   report_fatal_error("unsupported directive in streamer");
 212 }
 213
 214 void MCStreamer::emitGPRel32Value(const MCExpr *Value) {
 215   report_fatal_error("unsupported directive in streamer");
 216 }
 217
 218 /// Emit NumBytes bytes worth of the value specified by FillValue.
 219 /// This implements directives such as '.space'.
 220 void MCStreamer::emitFill(uint64_t NumBytes, uint8_t FillValue) {
 221   if (NumBytes)
 222     emitFill(*MCConstantExpr::create(NumBytes, getContext()), FillValue);
 223 }
 224
 225 void llvm::MCStreamer::emitNops(int64_t NumBytes, int64_t ControlledNopLen,
 226                                 llvm::SMLoc, const MCSubtargetInfo& STI) {}
 227
 228 /// The implementation in this class just redirects to emitFill.
 229 void MCStreamer::emitZeros(uint64_t NumBytes) { emitFill(NumBytes, 0); }
 230
 231 Expected<unsigned> MCStreamer::tryEmitDwarfFileDirective(
 232     unsigned FileNo, StringRef Directory, StringRef Filename,
 233     std::optional<MD5::MD5Result> Checksum, std::optional<StringRef> Source,
 234     unsigned CUID) {
 235   return getContext().getDwarfFile(Directory, Filename, FileNo, Checksum,
 236                                    Source, CUID);
 237 }
 238
 239 void MCStreamer::emitDwarfFile0Directive(StringRef Directory,
 240                                          StringRef Filename,
 241                                          std::optional<MD5::MD5Result> Checksum,
 242                                          std::optional<StringRef> Source,
 243                                          unsigned CUID) {
 244   getContext().setMCLineTableRootFile(CUID, Directory, Filename, Checksum,
 245                                       Source);
 246 }
 247
 248 void MCStreamer::emitCFIBKeyFrame() {
 249   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 250   if (!CurFrame)
 251     return;
 252   CurFrame->IsBKeyFrame = true;
 253 }
 254
 255 void MCStreamer::emitCFIMTETaggedFrame() {
 256   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 257   if (!CurFrame)
 258     return;
 259   CurFrame->IsMTETaggedFrame = true;
 260 }
 261
 262 void MCStreamer::emitDwarfLocDirective(unsigned FileNo, unsigned Line,
 263                                        unsigned Column, unsigned Flags,
 264                                        unsigned Isa, unsigned Discriminator,
 265                                        StringRef FileName) {
 266   getContext().setCurrentDwarfLoc(FileNo, Line, Column, Flags, Isa,
 267                                   Discriminator);
 268 }
 269
 270 MCSymbol *MCStreamer::getDwarfLineTableSymbol(unsigned CUID) {
 271   MCDwarfLineTable &Table = getContext().getMCDwarfLineTable(CUID);
 272   if (!Table.getLabel()) {
 273     StringRef Prefix = Context.getAsmInfo()->getPrivateGlobalPrefix();
 274     Table.setLabel(
 275         Context.getOrCreateSymbol(Prefix + "line_table_start" + Twine(CUID)));
 276   }
 277   return Table.getLabel();
 278 }
 279
 280 bool MCStreamer::hasUnfinishedDwarfFrameInfo() {
 281   return !FrameInfoStack.empty();
 282 }
 283
 284 MCDwarfFrameInfo *MCStreamer::getCurrentDwarfFrameInfo() {
 285   if (!hasUnfinishedDwarfFrameInfo()) {
 286     getContext().reportError(getStartTokLoc(),
 287                              "this directive must appear between "
 288                              ".cfi_startproc and .cfi_endproc directives");
 289     return nullptr;
 290   }
 291   return &DwarfFrameInfos[FrameInfoStack.back().first];
 292 }
 293
 294 bool MCStreamer::emitCVFileDirective(unsigned FileNo, StringRef Filename,
 295                                      ArrayRef<uint8_t> Checksum,
 296                                      unsigned ChecksumKind) {
 297   return getContext().getCVContext().addFile(*this, FileNo, Filename, Checksum,
 298                                              ChecksumKind);
 299 }
 300
 301 bool MCStreamer::emitCVFuncIdDirective(unsigned FunctionId) {
 302   return getContext().getCVContext().recordFunctionId(FunctionId);
 303 }
 304
 305 bool MCStreamer::emitCVInlineSiteIdDirective(unsigned FunctionId,
 306                                              unsigned IAFunc, unsigned IAFile,
 307                                              unsigned IALine, unsigned IACol,
 308                                              SMLoc Loc) {
 309   if (getContext().getCVContext().getCVFunctionInfo(IAFunc) == nullptr) {
 310     getContext().reportError(Loc, "parent function id not introduced by "
 311                                   ".cv_func_id or .cv_inline_site_id");
 312     return true;
 313   }
 314
 315   return getContext().getCVContext().recordInlinedCallSiteId(
 316       FunctionId, IAFunc, IAFile, IALine, IACol);
 317 }
 318
 319 void MCStreamer::emitCVLocDirective(unsigned FunctionId, unsigned FileNo,
 320                                     unsigned Line, unsigned Column,
 321                                     bool PrologueEnd, bool IsStmt,
 322                                     StringRef FileName, SMLoc Loc) {}
 323
 324 bool MCStreamer::checkCVLocSection(unsigned FuncId, unsigned FileNo,
 325                                    SMLoc Loc) {
 326   CodeViewContext &CVC = getContext().getCVContext();
 327   MCCVFunctionInfo *FI = CVC.getCVFunctionInfo(FuncId);
 328   if (!FI) {
 329     getContext().reportError(
 330         Loc, "function id not introduced by .cv_func_id or .cv_inline_site_id");
 331     return false;
 332   }
 333
 334   // Track the section
 335   if (FI->Section == nullptr)
 336     FI->Section = getCurrentSectionOnly();
 337   else if (FI->Section != getCurrentSectionOnly()) {
 338     getContext().reportError(
 339         Loc,
 340         "all .cv_loc directives for a function must be in the same section");
 341     return false;
 342   }
 343   return true;
 344 }
 345
 346 void MCStreamer::emitCVLinetableDirective(unsigned FunctionId,
 347                                           const MCSymbol *Begin,
 348                                           const MCSymbol *End) {}
 349
 350 void MCStreamer::emitCVInlineLinetableDirective(unsigned PrimaryFunctionId,
 351                                                 unsigned SourceFileId,
 352                                                 unsigned SourceLineNum,
 353                                                 const MCSymbol *FnStartSym,
 354                                                 const MCSymbol *FnEndSym) {}
 355
 356 /// Only call this on endian-specific types like ulittle16_t and little32_t, or
 357 /// structs composed of them.
 358 template <typename T>
 359 static void copyBytesForDefRange(SmallString<20> &BytePrefix,
 360                                  codeview::SymbolKind SymKind,
 361                                  const T &DefRangeHeader) {
 362   BytePrefix.resize(2 + sizeof(T));
 363   codeview::ulittle16_t SymKindLE = codeview::ulittle16_t(SymKind);
 364   memcpy(&BytePrefix[0], &SymKindLE, 2);
 365   memcpy(&BytePrefix[2], &DefRangeHeader, sizeof(T));
 366 }
 367
 368 void MCStreamer::emitCVDefRangeDirective(
 369     ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
 370     StringRef FixedSizePortion) {}
 371
 372 void MCStreamer::emitCVDefRangeDirective(
 373     ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
 374     codeview::DefRangeRegisterRelHeader DRHdr) {
 375   SmallString<20> BytePrefix;
 376   copyBytesForDefRange(BytePrefix, codeview::S_DEFRANGE_REGISTER_REL, DRHdr);
 377   emitCVDefRangeDirective(Ranges, BytePrefix);
 378 }
 379
 380 void MCStreamer::emitCVDefRangeDirective(
 381     ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
 382     codeview::DefRangeSubfieldRegisterHeader DRHdr) {
 383   SmallString<20> BytePrefix;
 384   copyBytesForDefRange(BytePrefix, codeview::S_DEFRANGE_SUBFIELD_REGISTER,
 385                        DRHdr);
 386   emitCVDefRangeDirective(Ranges, BytePrefix);
 387 }
 388
 389 void MCStreamer::emitCVDefRangeDirective(
 390     ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
 391     codeview::DefRangeRegisterHeader DRHdr) {
 392   SmallString<20> BytePrefix;
 393   copyBytesForDefRange(BytePrefix, codeview::S_DEFRANGE_REGISTER, DRHdr);
 394   emitCVDefRangeDirective(Ranges, BytePrefix);
 395 }
 396
 397 void MCStreamer::emitCVDefRangeDirective(
 398     ArrayRef<std::pair<const MCSymbol *, const MCSymbol *>> Ranges,
 399     codeview::DefRangeFramePointerRelHeader DRHdr) {
 400   SmallString<20> BytePrefix;
 401   copyBytesForDefRange(BytePrefix, codeview::S_DEFRANGE_FRAMEPOINTER_REL,
 402                        DRHdr);
 403   emitCVDefRangeDirective(Ranges, BytePrefix);
 404 }
 405
 406 void MCStreamer::emitEHSymAttributes(const MCSymbol *Symbol,
 407                                      MCSymbol *EHSymbol) {
 408 }
 409
 410 void MCStreamer::initSections(bool NoExecStack, const MCSubtargetInfo &STI) {
 411   switchSection(getContext().getObjectFileInfo()->getTextSection());
 412 }
 413
 414 void MCStreamer::emitLabel(MCSymbol *Symbol, SMLoc Loc) {
 415   Symbol->redefineIfPossible();
 416
 417   if (!Symbol->isUndefined() || Symbol->isVariable())
 418     return getContext().reportError(Loc, "symbol '" + Twine(Symbol->getName()) +
 419                                              "' is already defined");
 420
 421   assert(!Symbol->isVariable() && "Cannot emit a variable symbol!");
 422   assert(getCurrentSectionOnly() && "Cannot emit before setting section!");
 423   assert(!Symbol->getFragment() && "Unexpected fragment on symbol data!");
 424   assert(Symbol->isUndefined() && "Cannot define a symbol twice!");
 425
 426   Symbol->setFragment(&getCurrentSectionOnly()->getDummyFragment());
 427
 428   MCTargetStreamer *TS = getTargetStreamer();
 429   if (TS)
 430     TS->emitLabel(Symbol);
 431 }
 432
 433 void MCStreamer::emitConditionalAssignment(MCSymbol *Symbol,
 434                                            const MCExpr *Value) {}
 435
 436 void MCStreamer::emitCFISections(bool EH, bool Debug) {}
 437
 438 void MCStreamer::emitCFIStartProc(bool IsSimple, SMLoc Loc) {
 439   if (!FrameInfoStack.empty() &&
 440       getCurrentSectionOnly() == FrameInfoStack.back().second)
 441     return getContext().reportError(
 442         Loc, "starting new .cfi frame before finishing the previous one");
 443
 444   MCDwarfFrameInfo Frame;
 445   Frame.IsSimple = IsSimple;
 446   emitCFIStartProcImpl(Frame);
 447
 448   const MCAsmInfo* MAI = Context.getAsmInfo();
 449   if (MAI) {
 450     for (const MCCFIInstruction& Inst : MAI->getInitialFrameState()) {
 451       if (Inst.getOperation() == MCCFIInstruction::OpDefCfa ||
 452           Inst.getOperation() == MCCFIInstruction::OpDefCfaRegister ||
 453           Inst.getOperation() == MCCFIInstruction::OpLLVMDefAspaceCfa) {
 454         Frame.CurrentCfaRegister = Inst.getRegister();
 455       }
 456     }
 457   }
 458
 459   FrameInfoStack.emplace_back(DwarfFrameInfos.size(), getCurrentSectionOnly());
 460   DwarfFrameInfos.push_back(Frame);
 461 }
 462
 463 void MCStreamer::emitCFIStartProcImpl(MCDwarfFrameInfo &Frame) {
 464 }
 465
 466 void MCStreamer::emitCFIEndProc() {
 467   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 468   if (!CurFrame)
 469     return;
 470   emitCFIEndProcImpl(*CurFrame);
 471   FrameInfoStack.pop_back();
 472 }
 473
 474 void MCStreamer::emitCFIEndProcImpl(MCDwarfFrameInfo &Frame) {
 475   // Put a dummy non-null value in Frame.End to mark that this frame has been
 476   // closed.
 477   Frame.End = (MCSymbol *)1;
 478 }
 479
 480 MCSymbol *MCStreamer::emitCFILabel() {
 481   // Return a dummy non-null value so that label fields appear filled in when
 482   // generating textual assembly.
 483   return (MCSymbol *)1;
 484 }
 485
 486 void MCStreamer::emitCFIDefCfa(int64_t Register, int64_t Offset, SMLoc Loc) {
 487   MCSymbol *Label = emitCFILabel();
 488   MCCFIInstruction Instruction =
 489       MCCFIInstruction::cfiDefCfa(Label, Register, Offset, Loc);
 490   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 491   if (!CurFrame)
 492     return;
 493   CurFrame->Instructions.push_back(Instruction);
 494   CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
 495 }
 496
 497 void MCStreamer::emitCFIDefCfaOffset(int64_t Offset, SMLoc Loc) {
 498   MCSymbol *Label = emitCFILabel();
 499   MCCFIInstruction Instruction =
 500       MCCFIInstruction::cfiDefCfaOffset(Label, Offset);
 501   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 502   if (!CurFrame)
 503     return;
 504   CurFrame->Instructions.push_back(Instruction);
 505 }
 506
 507 void MCStreamer::emitCFIAdjustCfaOffset(int64_t Adjustment, SMLoc Loc) {
 508   MCSymbol *Label = emitCFILabel();
 509   MCCFIInstruction Instruction =
 510       MCCFIInstruction::createAdjustCfaOffset(Label, Adjustment, Loc);
 511   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 512   if (!CurFrame)
 513     return;
 514   CurFrame->Instructions.push_back(Instruction);
 515 }
 516
 517 void MCStreamer::emitCFIDefCfaRegister(int64_t Register, SMLoc Loc) {
 518   MCSymbol *Label = emitCFILabel();
 519   MCCFIInstruction Instruction =
 520       MCCFIInstruction::createDefCfaRegister(Label, Register, Loc);
 521   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 522   if (!CurFrame)
 523     return;
 524   CurFrame->Instructions.push_back(Instruction);
 525   CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
 526 }
 527
 528 void MCStreamer::emitCFILLVMDefAspaceCfa(int64_t Register, int64_t Offset,
 529                                          int64_t AddressSpace, SMLoc Loc) {
 530   MCSymbol *Label = emitCFILabel();
 531   MCCFIInstruction Instruction = MCCFIInstruction::createLLVMDefAspaceCfa(
 532       Label, Register, Offset, AddressSpace, Loc);
 533   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 534   if (!CurFrame)
 535     return;
 536   CurFrame->Instructions.push_back(Instruction);
 537   CurFrame->CurrentCfaRegister = static_cast<unsigned>(Register);
 538 }
 539
 540 void MCStreamer::emitCFIOffset(int64_t Register, int64_t Offset, SMLoc Loc) {
 541   MCSymbol *Label = emitCFILabel();
 542   MCCFIInstruction Instruction =
 543       MCCFIInstruction::createOffset(Label, Register, Offset, Loc);
 544   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 545   if (!CurFrame)
 546     return;
 547   CurFrame->Instructions.push_back(Instruction);
 548 }
 549
 550 void MCStreamer::emitCFIRelOffset(int64_t Register, int64_t Offset, SMLoc Loc) {
 551   MCSymbol *Label = emitCFILabel();
 552   MCCFIInstruction Instruction =
 553       MCCFIInstruction::createRelOffset(Label, Register, Offset, Loc);
 554   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 555   if (!CurFrame)
 556     return;
 557   CurFrame->Instructions.push_back(Instruction);
 558 }
 559
 560 void MCStreamer::emitCFIPersonality(const MCSymbol *Sym,
 561                                     unsigned Encoding) {
 562   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 563   if (!CurFrame)
 564     return;
 565   CurFrame->Personality = Sym;
 566   CurFrame->PersonalityEncoding = Encoding;
 567 }
 568
 569 void MCStreamer::emitCFILsda(const MCSymbol *Sym, unsigned Encoding) {
 570   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 571   if (!CurFrame)
 572     return;
 573   CurFrame->Lsda = Sym;
 574   CurFrame->LsdaEncoding = Encoding;
 575 }
 576
 577 void MCStreamer::emitCFIRememberState(SMLoc Loc) {
 578   MCSymbol *Label = emitCFILabel();
 579   MCCFIInstruction Instruction =
 580       MCCFIInstruction::createRememberState(Label, Loc);
 581   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 582   if (!CurFrame)
 583     return;
 584   CurFrame->Instructions.push_back(Instruction);
 585 }
 586
 587 void MCStreamer::emitCFIRestoreState(SMLoc Loc) {
 588   // FIXME: Error if there is no matching cfi_remember_state.
 589   MCSymbol *Label = emitCFILabel();
 590   MCCFIInstruction Instruction =
 591       MCCFIInstruction::createRestoreState(Label, Loc);
 592   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 593   if (!CurFrame)
 594     return;
 595   CurFrame->Instructions.push_back(Instruction);
 596 }
 597
 598 void MCStreamer::emitCFISameValue(int64_t Register, SMLoc Loc) {
 599   MCSymbol *Label = emitCFILabel();
 600   MCCFIInstruction Instruction =
 601       MCCFIInstruction::createSameValue(Label, Register, Loc);
 602   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 603   if (!CurFrame)
 604     return;
 605   CurFrame->Instructions.push_back(Instruction);
 606 }
 607
 608 void MCStreamer::emitCFIRestore(int64_t Register, SMLoc Loc) {
 609   MCSymbol *Label = emitCFILabel();
 610   MCCFIInstruction Instruction =
 611       MCCFIInstruction::createRestore(Label, Register, Loc);
 612   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 613   if (!CurFrame)
 614     return;
 615   CurFrame->Instructions.push_back(Instruction);
 616 }
 617
 618 void MCStreamer::emitCFIEscape(StringRef Values, SMLoc Loc) {
 619   MCSymbol *Label = emitCFILabel();
 620   MCCFIInstruction Instruction =
 621       MCCFIInstruction::createEscape(Label, Values, Loc, "");
 622   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 623   if (!CurFrame)
 624     return;
 625   CurFrame->Instructions.push_back(Instruction);
 626 }
 627
 628 void MCStreamer::emitCFIGnuArgsSize(int64_t Size, SMLoc Loc) {
 629   MCSymbol *Label = emitCFILabel();
 630   MCCFIInstruction Instruction =
 631       MCCFIInstruction::createGnuArgsSize(Label, Size, Loc);
 632   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 633   if (!CurFrame)
 634     return;
 635   CurFrame->Instructions.push_back(Instruction);
 636 }
 637
 638 void MCStreamer::emitCFISignalFrame() {
 639   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 640   if (!CurFrame)
 641     return;
 642   CurFrame->IsSignalFrame = true;
 643 }
 644
 645 void MCStreamer::emitCFIUndefined(int64_t Register, SMLoc Loc) {
 646   MCSymbol *Label = emitCFILabel();
 647   MCCFIInstruction Instruction =
 648       MCCFIInstruction::createUndefined(Label, Register, Loc);
 649   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 650   if (!CurFrame)
 651     return;
 652   CurFrame->Instructions.push_back(Instruction);
 653 }
 654
 655 void MCStreamer::emitCFIRegister(int64_t Register1, int64_t Register2,
 656                                  SMLoc Loc) {
 657   MCSymbol *Label = emitCFILabel();
 658   MCCFIInstruction Instruction =
 659       MCCFIInstruction::createRegister(Label, Register1, Register2, Loc);
 660   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 661   if (!CurFrame)
 662     return;
 663   CurFrame->Instructions.push_back(Instruction);
 664 }
 665
 666 void MCStreamer::emitCFIWindowSave(SMLoc Loc) {
 667   MCSymbol *Label = emitCFILabel();
 668   MCCFIInstruction Instruction = MCCFIInstruction::createWindowSave(Label, Loc);
 669   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 670   if (!CurFrame)
 671     return;
 672   CurFrame->Instructions.push_back(Instruction);
 673 }
 674
 675 void MCStreamer::emitCFINegateRAState(SMLoc Loc) {
 676   MCSymbol *Label = emitCFILabel();
 677   MCCFIInstruction Instruction =
 678       MCCFIInstruction::createNegateRAState(Label, Loc);
 679   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 680   if (!CurFrame)
 681     return;
 682   CurFrame->Instructions.push_back(Instruction);
 683 }
 684
 685 void MCStreamer::emitCFIReturnColumn(int64_t Register) {
 686   MCDwarfFrameInfo *CurFrame = getCurrentDwarfFrameInfo();
 687   if (!CurFrame)
 688     return;
 689   CurFrame->RAReg = Register;
 690 }
 691
 692 void MCStreamer::emitCFILabelDirective(SMLoc Loc, StringRef Name) {
 693   MCSymbol *Label = emitCFILabel();
 694   MCSymbol *Sym = getContext().getOrCreateSymbol(Name);
 695   if (MCDwarfFrameInfo *F = getCurrentDwarfFrameInfo())
 696     F->Instructions.push_back(MCCFIInstruction::createLabel(Label, Sym, Loc));
 697 }
 698
 699 WinEH::FrameInfo *MCStreamer::EnsureValidWinFrameInfo(SMLoc Loc) {
 700   const MCAsmInfo *MAI = Context.getAsmInfo();
 701   if (!MAI->usesWindowsCFI()) {
 702     getContext().reportError(
 703         Loc, ".seh_* directives are not supported on this target");
 704     return nullptr;
 705   }
 706   if (!CurrentWinFrameInfo || CurrentWinFrameInfo->End) {
 707     getContext().reportError(
 708         Loc, ".seh_ directive must appear within an active frame");
 709     return nullptr;
 710   }
 711   return CurrentWinFrameInfo;
 712 }
 713
 714 void MCStreamer::emitWinCFIStartProc(const MCSymbol *Symbol, SMLoc Loc) {
 715   const MCAsmInfo *MAI = Context.getAsmInfo();
 716   if (!MAI->usesWindowsCFI())
 717     return getContext().reportError(
 718         Loc, ".seh_* directives are not supported on this target");
 719   if (CurrentWinFrameInfo && !CurrentWinFrameInfo->End)
 720     getContext().reportError(
 721         Loc, "Starting a function before ending the previous one!");
 722
 723   MCSymbol *StartProc = emitCFILabel();
 724
 725   CurrentProcWinFrameInfoStartIndex = WinFrameInfos.size();
 726   WinFrameInfos.emplace_back(
 727       std::make_unique<WinEH::FrameInfo>(Symbol, StartProc));
 728   CurrentWinFrameInfo = WinFrameInfos.back().get();
 729   CurrentWinFrameInfo->TextSection = getCurrentSectionOnly();
 730 }
 731
 732 void MCStreamer::emitWinCFIEndProc(SMLoc Loc) {
 733   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 734   if (!CurFrame)
 735     return;
 736   if (CurFrame->ChainedParent)
 737     getContext().reportError(Loc, "Not all chained regions terminated!");
 738
 739   MCSymbol *Label = emitCFILabel();
 740   CurFrame->End = Label;
 741   if (!CurFrame->FuncletOrFuncEnd)
 742     CurFrame->FuncletOrFuncEnd = CurFrame->End;
 743
 744   for (size_t I = CurrentProcWinFrameInfoStartIndex, E = WinFrameInfos.size();
 745        I != E; ++I)
 746     emitWindowsUnwindTables(WinFrameInfos[I].get());
 747   switchSection(CurFrame->TextSection);
 748 }
 749
 750 void MCStreamer::emitWinCFIFuncletOrFuncEnd(SMLoc Loc) {
 751   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 752   if (!CurFrame)
 753     return;
 754   if (CurFrame->ChainedParent)
 755     getContext().reportError(Loc, "Not all chained regions terminated!");
 756
 757   MCSymbol *Label = emitCFILabel();
 758   CurFrame->FuncletOrFuncEnd = Label;
 759 }
 760
 761 void MCStreamer::emitWinCFIStartChained(SMLoc Loc) {
 762   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 763   if (!CurFrame)
 764     return;
 765
 766   MCSymbol *StartProc = emitCFILabel();
 767
 768   WinFrameInfos.emplace_back(std::make_unique<WinEH::FrameInfo>(
 769       CurFrame->Function, StartProc, CurFrame));
 770   CurrentWinFrameInfo = WinFrameInfos.back().get();
 771   CurrentWinFrameInfo->TextSection = getCurrentSectionOnly();
 772 }
 773
 774 void MCStreamer::emitWinCFIEndChained(SMLoc Loc) {
 775   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 776   if (!CurFrame)
 777     return;
 778   if (!CurFrame->ChainedParent)
 779     return getContext().reportError(
 780         Loc, "End of a chained region outside a chained region!");
 781
 782   MCSymbol *Label = emitCFILabel();
 783
 784   CurFrame->End = Label;
 785   CurrentWinFrameInfo = const_cast<WinEH::FrameInfo *>(CurFrame->ChainedParent);
 786 }
 787
 788 void MCStreamer::emitWinEHHandler(const MCSymbol *Sym, bool Unwind, bool Except,
 789                                   SMLoc Loc) {
 790   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 791   if (!CurFrame)
 792     return;
 793   if (CurFrame->ChainedParent)
 794     return getContext().reportError(
 795         Loc, "Chained unwind areas can't have handlers!");
 796   CurFrame->ExceptionHandler = Sym;
 797   if (!Except && !Unwind)
 798     getContext().reportError(Loc, "Don't know what kind of handler this is!");
 799   if (Unwind)
 800     CurFrame->HandlesUnwind = true;
 801   if (Except)
 802     CurFrame->HandlesExceptions = true;
 803 }
 804
 805 void MCStreamer::emitWinEHHandlerData(SMLoc Loc) {
 806   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 807   if (!CurFrame)
 808     return;
 809   if (CurFrame->ChainedParent)
 810     getContext().reportError(Loc, "Chained unwind areas can't have handlers!");
 811 }
 812
 813 void MCStreamer::emitCGProfileEntry(const MCSymbolRefExpr *From,
 814                                     const MCSymbolRefExpr *To, uint64_t Count) {
 815 }
 816
 817 static MCSection *getWinCFISection(MCContext &Context, unsigned *NextWinCFIID,
 818                                    MCSection *MainCFISec,
 819                                    const MCSection *TextSec) {
 820   // If this is the main .text section, use the main unwind info section.
 821   if (TextSec == Context.getObjectFileInfo()->getTextSection())
 822     return MainCFISec;
 823
 824   const auto *TextSecCOFF = cast<MCSectionCOFF>(TextSec);
 825   auto *MainCFISecCOFF = cast<MCSectionCOFF>(MainCFISec);
 826   unsigned UniqueID = TextSecCOFF->getOrAssignWinCFISectionID(NextWinCFIID);
 827
 828   // If this section is COMDAT, this unwind section should be COMDAT associative
 829   // with its group.
 830   const MCSymbol *KeySym = nullptr;
 831   if (TextSecCOFF->getCharacteristics() & COFF::IMAGE_SCN_LNK_COMDAT) {
 832     KeySym = TextSecCOFF->getCOMDATSymbol();
 833
 834     // In a GNU environment, we can't use associative comdats. Instead, do what
 835     // GCC does, which is to make plain comdat selectany section named like
 836     // ".[px]data$_Z3foov".
 837     if (!Context.getAsmInfo()->hasCOFFAssociativeComdats()) {
 838       std::string SectionName = (MainCFISecCOFF->getName() + "$" +
 839                                  TextSecCOFF->getName().split('$').second)
 840                                     .str();
 841       return Context.getCOFFSection(SectionName,
 842                                     MainCFISecCOFF->getCharacteristics() |
 843                                         COFF::IMAGE_SCN_LNK_COMDAT,
 844                                     "", COFF::IMAGE_COMDAT_SELECT_ANY);
 845     }
 846   }
 847
 848   return Context.getAssociativeCOFFSection(MainCFISecCOFF, KeySym, UniqueID);
 849 }
 850
 851 MCSection *MCStreamer::getAssociatedPDataSection(const MCSection *TextSec) {
 852   return getWinCFISection(getContext(), &NextWinCFIID,
 853                           getContext().getObjectFileInfo()->getPDataSection(),
 854                           TextSec);
 855 }
 856
 857 MCSection *MCStreamer::getAssociatedXDataSection(const MCSection *TextSec) {
 858   return getWinCFISection(getContext(), &NextWinCFIID,
 859                           getContext().getObjectFileInfo()->getXDataSection(),
 860                           TextSec);
 861 }
 862
 863 void MCStreamer::emitSyntaxDirective() {}
 864
 865 static unsigned encodeSEHRegNum(MCContext &Ctx, MCRegister Reg) {
 866   return Ctx.getRegisterInfo()->getSEHRegNum(Reg);
 867 }
 868
 869 void MCStreamer::emitWinCFIPushReg(MCRegister Register, SMLoc Loc) {
 870   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 871   if (!CurFrame)
 872     return;
 873
 874   MCSymbol *Label = emitCFILabel();
 875
 876   WinEH::Instruction Inst = Win64EH::Instruction::PushNonVol(
 877       Label, encodeSEHRegNum(Context, Register));
 878   CurFrame->Instructions.push_back(Inst);
 879 }
 880
 881 void MCStreamer::emitWinCFISetFrame(MCRegister Register, unsigned Offset,
 882                                     SMLoc Loc) {
 883   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 884   if (!CurFrame)
 885     return;
 886   if (CurFrame->LastFrameInst >= 0)
 887     return getContext().reportError(
 888         Loc, "frame register and offset can be set at most once");
 889   if (Offset & 0x0F)
 890     return getContext().reportError(Loc, "offset is not a multiple of 16");
 891   if (Offset > 240)
 892     return getContext().reportError(
 893         Loc, "frame offset must be less than or equal to 240");
 894
 895   MCSymbol *Label = emitCFILabel();
 896
 897   WinEH::Instruction Inst = Win64EH::Instruction::SetFPReg(
 898       Label, encodeSEHRegNum(getContext(), Register), Offset);
 899   CurFrame->LastFrameInst = CurFrame->Instructions.size();
 900   CurFrame->Instructions.push_back(Inst);
 901 }
 902
 903 void MCStreamer::emitWinCFIAllocStack(unsigned Size, SMLoc Loc) {
 904   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 905   if (!CurFrame)
 906     return;
 907   if (Size == 0)
 908     return getContext().reportError(Loc,
 909                                     "stack allocation size must be non-zero");
 910   if (Size & 7)
 911     return getContext().reportError(
 912         Loc, "stack allocation size is not a multiple of 8");
 913
 914   MCSymbol *Label = emitCFILabel();
 915
 916   WinEH::Instruction Inst = Win64EH::Instruction::Alloc(Label, Size);
 917   CurFrame->Instructions.push_back(Inst);
 918 }
 919
 920 void MCStreamer::emitWinCFISaveReg(MCRegister Register, unsigned Offset,
 921                                    SMLoc Loc) {
 922   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 923   if (!CurFrame)
 924     return;
 925
 926   if (Offset & 7)
 927     return getContext().reportError(
 928         Loc, "register save offset is not 8 byte aligned");
 929
 930   MCSymbol *Label = emitCFILabel();
 931
 932   WinEH::Instruction Inst = Win64EH::Instruction::SaveNonVol(
 933       Label, encodeSEHRegNum(Context, Register), Offset);
 934   CurFrame->Instructions.push_back(Inst);
 935 }
 936
 937 void MCStreamer::emitWinCFISaveXMM(MCRegister Register, unsigned Offset,
 938                                    SMLoc Loc) {
 939   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 940   if (!CurFrame)
 941     return;
 942   if (Offset & 0x0F)
 943     return getContext().reportError(Loc, "offset is not a multiple of 16");
 944
 945   MCSymbol *Label = emitCFILabel();
 946
 947   WinEH::Instruction Inst = Win64EH::Instruction::SaveXMM(
 948       Label, encodeSEHRegNum(Context, Register), Offset);
 949   CurFrame->Instructions.push_back(Inst);
 950 }
 951
 952 void MCStreamer::emitWinCFIPushFrame(bool Code, SMLoc Loc) {
 953   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 954   if (!CurFrame)
 955     return;
 956   if (!CurFrame->Instructions.empty())
 957     return getContext().reportError(
 958         Loc, "If present, PushMachFrame must be the first UOP");
 959
 960   MCSymbol *Label = emitCFILabel();
 961
 962   WinEH::Instruction Inst = Win64EH::Instruction::PushMachFrame(Label, Code);
 963   CurFrame->Instructions.push_back(Inst);
 964 }
 965
 966 void MCStreamer::emitWinCFIEndProlog(SMLoc Loc) {
 967   WinEH::FrameInfo *CurFrame = EnsureValidWinFrameInfo(Loc);
 968   if (!CurFrame)
 969     return;
 970
 971   MCSymbol *Label = emitCFILabel();
 972
 973   CurFrame->PrologEnd = Label;
 974 }
 975
 976 void MCStreamer::emitCOFFSafeSEH(MCSymbol const *Symbol) {}
 977
 978 void MCStreamer::emitCOFFSymbolIndex(MCSymbol const *Symbol) {}
 979
 980 void MCStreamer::emitCOFFSectionIndex(MCSymbol const *Symbol) {}
 981
 982 void MCStreamer::emitCOFFSecRel32(MCSymbol const *Symbol, uint64_t Offset) {}
 983
 984 void MCStreamer::emitCOFFImgRel32(MCSymbol const *Symbol, int64_t Offset) {}
 985
 986 /// EmitRawText - If this file is backed by an assembly streamer, this dumps
 987 /// the specified string in the output .s file.  This capability is
 988 /// indicated by the hasRawTextSupport() predicate.
 989 void MCStreamer::emitRawTextImpl(StringRef String) {
 990   // This is not llvm_unreachable for the sake of out of tree backend
 991   // developers who may not have assembly streamers and should serve as a
 992   // reminder to not accidentally call EmitRawText in the absence of such.
 993   report_fatal_error("EmitRawText called on an MCStreamer that doesn't support "
 994                      "it (target backend is likely missing an AsmStreamer "
 995                      "implementation)");
 996 }
 997
 998 void MCStreamer::emitRawText(const Twine &T) {
 999   SmallString<128> Str;
1000   emitRawTextImpl(T.toStringRef(Str));
1001 }
1002
1003 void MCStreamer::emitWindowsUnwindTables() {}
1004
1005 void MCStreamer::emitWindowsUnwindTables(WinEH::FrameInfo *Frame) {}
1006
1007 void MCStreamer::finish(SMLoc EndLoc) {
1008   if ((!DwarfFrameInfos.empty() && !DwarfFrameInfos.back().End) ||
1009       (!WinFrameInfos.empty() && !WinFrameInfos.back()->End)) {
1010     getContext().reportError(EndLoc, "Unfinished frame!");
1011     return;
1012   }
1013
1014   MCTargetStreamer *TS = getTargetStreamer();
1015   if (TS)
1016     TS->finish();
1017
1018   finishImpl();
1019 }
1020
1021 void MCStreamer::maybeEmitDwarf64Mark() {
1022   if (Context.getDwarfFormat() != dwarf::DWARF64)
1023     return;
1024   AddComment("DWARF64 Mark");
1025   emitInt32(dwarf::DW_LENGTH_DWARF64);
1026 }
1027
1028 void MCStreamer::emitDwarfUnitLength(uint64_t Length, const Twine &Comment) {
1029   assert(Context.getDwarfFormat() == dwarf::DWARF64 ||
1030          Length <= dwarf::DW_LENGTH_lo_reserved);
1031   maybeEmitDwarf64Mark();
1032   AddComment(Comment);
1033   emitIntValue(Length, dwarf::getDwarfOffsetByteSize(Context.getDwarfFormat()));
1034 }
1035
1036 MCSymbol *MCStreamer::emitDwarfUnitLength(const Twine &Prefix,
1037                                           const Twine &Comment) {
1038   maybeEmitDwarf64Mark();
1039   AddComment(Comment);
1040   MCSymbol *Lo = Context.createTempSymbol(Prefix + "_start");
1041   MCSymbol *Hi = Context.createTempSymbol(Prefix + "_end");
1042
1043   emitAbsoluteSymbolDiff(
1044       Hi, Lo, dwarf::getDwarfOffsetByteSize(Context.getDwarfFormat()));
1045   // emit the begin symbol after we generate the length field.
1046   emitLabel(Lo);
1047   // Return the Hi symbol to the caller.
1048   return Hi;
1049 }
1050
1051 void MCStreamer::emitDwarfLineStartLabel(MCSymbol *StartSym) {
1052   // Set the value of the symbol, as we are at the start of the line table.
1053   emitLabel(StartSym);
1054 }
1055
1056 void MCStreamer::emitAssignment(MCSymbol *Symbol, const MCExpr *Value) {
1057   visitUsedExpr(*Value);
1058   Symbol->setVariableValue(Value);
1059
1060   MCTargetStreamer *TS = getTargetStreamer();
1061   if (TS)
1062     TS->emitAssignment(Symbol, Value);
1063 }
1064
1065 void MCTargetStreamer::prettyPrintAsm(MCInstPrinter &InstPrinter,
1066                                       uint64_t Address, const MCInst &Inst,
1067                                       const MCSubtargetInfo &STI,
1068                                       raw_ostream &OS) {
1069   InstPrinter.printInst(&Inst, Address, "", STI, OS);
1070 }
1071
1072 void MCStreamer::visitUsedSymbol(const MCSymbol &Sym) {
1073 }
1074
1075 void MCStreamer::visitUsedExpr(const MCExpr &Expr) {
1076   switch (Expr.getKind()) {
1077   case MCExpr::Target:
1078     cast<MCTargetExpr>(Expr).visitUsedExpr(*this);
1079     break;
1080
1081   case MCExpr::Constant:
1082     break;
1083
1084   case MCExpr::Binary: {
1085     const MCBinaryExpr &BE = cast<MCBinaryExpr>(Expr);
1086     visitUsedExpr(*BE.getLHS());
1087     visitUsedExpr(*BE.getRHS());
1088     break;
1089   }
1090
1091   case MCExpr::SymbolRef:
1092     visitUsedSymbol(cast<MCSymbolRefExpr>(Expr).getSymbol());
1093     break;
1094
1095   case MCExpr::Unary:
1096     visitUsedExpr(*cast<MCUnaryExpr>(Expr).getSubExpr());
1097     break;
1098   }
1099 }
1100
1101 void MCStreamer::emitInstruction(const MCInst &Inst, const MCSubtargetInfo &) {
1102   // Scan for values.
1103   for (unsigned i = Inst.getNumOperands(); i--;)
1104     if (Inst.getOperand(i).isExpr())
1105       visitUsedExpr(*Inst.getOperand(i).getExpr());
1106 }
1107
1108 void MCStreamer::emitPseudoProbe(uint64_t Guid, uint64_t Index, uint64_t Type,
1109                                  uint64_t Attr, uint64_t Discriminator,
1110                                  const MCPseudoProbeInlineStack &InlineStack,
1111                                  MCSymbol *FnSym) {
1112   auto &Context = getContext();
1113
1114   // Create a symbol at in the current section for use in the probe.
1115   MCSymbol *ProbeSym = Context.createTempSymbol();
1116
1117   // Set the value of the symbol to use for the MCPseudoProbe.
1118   emitLabel(ProbeSym);
1119
1120   // Create a (local) probe entry with the symbol.
1121   MCPseudoProbe Probe(ProbeSym, Guid, Index, Type, Attr, Discriminator);
1122
1123   // Add the probe entry to this section's entries.
1124   Context.getMCPseudoProbeTable().getProbeSections().addPseudoProbe(
1125       FnSym, Probe, InlineStack);
1126 }
1127
1128 void MCStreamer::emitAbsoluteSymbolDiff(const MCSymbol *Hi, const MCSymbol *Lo,
1129                                         unsigned Size) {
1130   // Get the Hi-Lo expression.
1131   const MCExpr *Diff =
1132       MCBinaryExpr::createSub(MCSymbolRefExpr::create(Hi, Context),
1133                               MCSymbolRefExpr::create(Lo, Context), Context);
1134
1135   const MCAsmInfo *MAI = Context.getAsmInfo();
1136   if (!MAI->doesSetDirectiveSuppressReloc()) {
1137     emitValue(Diff, Size);
1138     return;
1139   }
1140
1141   // Otherwise, emit with .set (aka assignment).
1142   MCSymbol *SetLabel = Context.createTempSymbol("set");
1143   emitAssignment(SetLabel, Diff);
1144   emitSymbolValue(SetLabel, Size);
1145 }
1146
1147 void MCStreamer::emitAbsoluteSymbolDiffAsULEB128(const MCSymbol *Hi,
1148                                                  const MCSymbol *Lo) {
1149   // Get the Hi-Lo expression.
1150   const MCExpr *Diff =
1151       MCBinaryExpr::createSub(MCSymbolRefExpr::create(Hi, Context),
1152                               MCSymbolRefExpr::create(Lo, Context), Context);
1153
1154   emitULEB128Value(Diff);
1155 }
1156
1157 void MCStreamer::emitAssemblerFlag(MCAssemblerFlag Flag) {}
1158 void MCStreamer::emitThumbFunc(MCSymbol *Func) {}
1159 void MCStreamer::emitSymbolDesc(MCSymbol *Symbol, unsigned DescValue) {}
1160 void MCStreamer::beginCOFFSymbolDef(const MCSymbol *Symbol) {
1161   llvm_unreachable("this directive only supported on COFF targets");
1162 }
1163 void MCStreamer::endCOFFSymbolDef() {
1164   llvm_unreachable("this directive only supported on COFF targets");
1165 }
1166 void MCStreamer::emitFileDirective(StringRef Filename) {}
1167 void MCStreamer::emitFileDirective(StringRef Filename,
1168                                    StringRef CompilerVersion,
1169                                    StringRef TimeStamp, StringRef Description) {
1170 }
1171 void MCStreamer::emitCOFFSymbolStorageClass(int StorageClass) {
1172   llvm_unreachable("this directive only supported on COFF targets");
1173 }
1174 void MCStreamer::emitCOFFSymbolType(int Type) {
1175   llvm_unreachable("this directive only supported on COFF targets");
1176 }
1177 void MCStreamer::emitXCOFFLocalCommonSymbol(MCSymbol *LabelSym, uint64_t Size,
1178                                             MCSymbol *CsectSym,
1179                                             Align Alignment) {
1180   llvm_unreachable("this directive only supported on XCOFF targets");
1181 }
1182
1183 void MCStreamer::emitXCOFFSymbolLinkageWithVisibility(MCSymbol *Symbol,
1184                                                       MCSymbolAttr Linkage,
1185                                                       MCSymbolAttr Visibility) {
1186   llvm_unreachable("emitXCOFFSymbolLinkageWithVisibility is only supported on "
1187                    "XCOFF targets");
1188 }
1189
1190 void MCStreamer::emitXCOFFRenameDirective(const MCSymbol *Name,
1191                                           StringRef Rename) {}
1192
1193 void MCStreamer::emitXCOFFRefDirective(const MCSymbol *Symbol) {
1194   llvm_unreachable("emitXCOFFRefDirective is only supported on XCOFF targets");
1195 }
1196
1197 void MCStreamer::emitXCOFFExceptDirective(const MCSymbol *Symbol,
1198                                           const MCSymbol *Trap,
1199                                           unsigned Lang, unsigned Reason,
1200                                           unsigned FunctionSize,
1201                                           bool hasDebug) {
1202   report_fatal_error("emitXCOFFExceptDirective is only supported on "
1203                      "XCOFF targets");
1204 }
1205
1206 void MCStreamer::emitXCOFFCInfoSym(StringRef Name, StringRef Metadata) {
1207   llvm_unreachable("emitXCOFFCInfoSym is only supported on"
1208                    "XCOFF targets");
1209 }
1210
1211 void MCStreamer::emitELFSize(MCSymbol *Symbol, const MCExpr *Value) {}
1212 void MCStreamer::emitELFSymverDirective(const MCSymbol *OriginalSym,
1213                                         StringRef Name, bool KeepOriginalSym) {}
1214 void MCStreamer::emitLocalCommonSymbol(MCSymbol *Symbol, uint64_t Size,
1215                                        Align ByteAlignment) {}
1216 void MCStreamer::emitTBSSSymbol(MCSection *Section, MCSymbol *Symbol,
1217                                 uint64_t Size, Align ByteAlignment) {}
1218 void MCStreamer::changeSection(MCSection *Section, uint32_t) {
1219   CurFrag = &Section->getDummyFragment();
1220 }
1221 void MCStreamer::emitWeakReference(MCSymbol *Alias, const MCSymbol *Symbol) {}
1222 void MCStreamer::emitBytes(StringRef Data) {}
1223 void MCStreamer::emitBinaryData(StringRef Data) { emitBytes(Data); }
1224 void MCStreamer::emitValueImpl(const MCExpr *Value, unsigned Size, SMLoc Loc) {
1225   visitUsedExpr(*Value);
1226 }
1227 void MCStreamer::emitULEB128Value(const MCExpr *Value) {}
1228 void MCStreamer::emitSLEB128Value(const MCExpr *Value) {}
1229 void MCStreamer::emitFill(const MCExpr &NumBytes, uint64_t Value, SMLoc Loc) {}
1230 void MCStreamer::emitFill(const MCExpr &NumValues, int64_t Size, int64_t Expr,
1231                           SMLoc Loc) {}
1232 void MCStreamer::emitValueToAlignment(Align Alignment, int64_t Value,
1233                                       unsigned ValueSize,
1234                                       unsigned MaxBytesToEmit) {}
1235 void MCStreamer::emitCodeAlignment(Align Alignment, const MCSubtargetInfo *STI,
1236                                    unsigned MaxBytesToEmit) {}
1237 void MCStreamer::emitValueToOffset(const MCExpr *Offset, unsigned char Value,
1238                                    SMLoc Loc) {}
1239 void MCStreamer::emitBundleAlignMode(Align Alignment) {}
1240 void MCStreamer::emitBundleLock(bool AlignToEnd) {}
1241 void MCStreamer::finishImpl() {}
1242 void MCStreamer::emitBundleUnlock() {}
1243
1244 bool MCStreamer::popSection() {
1245   if (SectionStack.size() <= 1)
1246     return false;
1247   auto I = SectionStack.end();
1248   --I;
1249   MCSectionSubPair OldSec = I->first;
1250   --I;
1251   MCSectionSubPair NewSec = I->first;
1252
1253   if (NewSec.first && OldSec != NewSec)
1254     changeSection(NewSec.first, NewSec.second);
1255   SectionStack.pop_back();
1256   return true;
1257 }
1258
1259 void MCStreamer::switchSection(MCSection *Section, uint32_t Subsection) {
1260   assert(Section && "Cannot switch to a null section!");
1261   MCSectionSubPair curSection = SectionStack.back().first;
1262   SectionStack.back().second = curSection;
1263   if (MCSectionSubPair(Section, Subsection) != curSection) {
1264     changeSection(Section, Subsection);
1265     SectionStack.back().first = MCSectionSubPair(Section, Subsection);
1266     assert(!Section->hasEnded() && "Section already ended");
1267     MCSymbol *Sym = Section->getBeginSymbol();
1268     if (Sym && !Sym->isInSection())
1269       emitLabel(Sym);
1270   }
1271 }
1272
1273 bool MCStreamer::switchSection(MCSection *Section, const MCExpr *SubsecExpr) {
1274   int64_t Subsec = 0;
1275   if (SubsecExpr) {
1276     if (!SubsecExpr->evaluateAsAbsolute(Subsec, getAssemblerPtr())) {
1277       getContext().reportError(SubsecExpr->getLoc(),
1278                                "cannot evaluate subsection number");
1279       return true;
1280     }
1281     if (!isUInt<31>(Subsec)) {
1282       getContext().reportError(SubsecExpr->getLoc(),
1283                                "subsection number " + Twine(Subsec) +
1284                                    " is not within [0,2147483647]");
1285       return true;
1286     }
1287   }
1288   switchSection(Section, Subsec);
1289   return false;
1290 }
1291
1292 void MCStreamer::switchSectionNoPrint(MCSection *Section) {
1293   SectionStack.back().second = SectionStack.back().first;
1294   SectionStack.back().first = MCSectionSubPair(Section, 0);
1295   CurFrag = &Section->getDummyFragment();
1296 }
1297
1298 MCSymbol *MCStreamer::endSection(MCSection *Section) {
1299   // TODO: keep track of the last subsection so that this symbol appears in the
1300   // correct place.
1301   MCSymbol *Sym = Section->getEndSymbol(Context);
1302   if (Sym->isInSection())
1303     return Sym;
1304
1305   switchSection(Section);
1306   emitLabel(Sym);
1307   return Sym;
1308 }
1309
1310 static VersionTuple
1311 targetVersionOrMinimumSupportedOSVersion(const Triple &Target,
1312                                          VersionTuple TargetVersion) {
1313   VersionTuple Min = Target.getMinimumSupportedOSVersion();
1314   return !Min.empty() && Min > TargetVersion ? Min : TargetVersion;
1315 }
1316
1317 static MCVersionMinType
1318 getMachoVersionMinLoadCommandType(const Triple &Target) {
1319   assert(Target.isOSDarwin() && "expected a darwin OS");
1320   switch (Target.getOS()) {
1321   case Triple::MacOSX:
1322   case Triple::Darwin:
1323     return MCVM_OSXVersionMin;
1324   case Triple::IOS:
1325     assert(!Target.isMacCatalystEnvironment() &&
1326            "mac Catalyst should use LC_BUILD_VERSION");
1327     return MCVM_IOSVersionMin;
1328   case Triple::TvOS:
1329     return MCVM_TvOSVersionMin;
1330   case Triple::WatchOS:
1331     return MCVM_WatchOSVersionMin;
1332   default:
1333     break;
1334   }
1335   llvm_unreachable("unexpected OS type");
1336 }
1337
1338 static VersionTuple getMachoBuildVersionSupportedOS(const Triple &Target) {
1339   assert(Target.isOSDarwin() && "expected a darwin OS");
1340   switch (Target.getOS()) {
1341   case Triple::MacOSX:
1342   case Triple::Darwin:
1343     return VersionTuple(10, 14);
1344   case Triple::IOS:
1345     // Mac Catalyst always uses the build version load command.
1346     if (Target.isMacCatalystEnvironment())
1347       return VersionTuple();
1348     [[fallthrough]];
1349   case Triple::TvOS:
1350     return VersionTuple(12);
1351   case Triple::WatchOS:
1352     return VersionTuple(5);
1353   case Triple::DriverKit:
1354     // DriverKit always uses the build version load command.
1355     return VersionTuple();
1356   case Triple::XROS:
1357     // XROS always uses the build version load command.
1358     return VersionTuple();
1359   default:
1360     break;
1361   }
1362   llvm_unreachable("unexpected OS type");
1363 }
1364
1365 static MachO::PlatformType
1366 getMachoBuildVersionPlatformType(const Triple &Target) {
1367   assert(Target.isOSDarwin() && "expected a darwin OS");
1368   switch (Target.getOS()) {
1369   case Triple::MacOSX:
1370   case Triple::Darwin:
1371     return MachO::PLATFORM_MACOS;
1372   case Triple::IOS:
1373     if (Target.isMacCatalystEnvironment())
1374       return MachO::PLATFORM_MACCATALYST;
1375     return Target.isSimulatorEnvironment() ? MachO::PLATFORM_IOSSIMULATOR
1376                                            : MachO::PLATFORM_IOS;
1377   case Triple::TvOS:
1378     return Target.isSimulatorEnvironment() ? MachO::PLATFORM_TVOSSIMULATOR
1379                                            : MachO::PLATFORM_TVOS;
1380   case Triple::WatchOS:
1381     return Target.isSimulatorEnvironment() ? MachO::PLATFORM_WATCHOSSIMULATOR
1382                                            : MachO::PLATFORM_WATCHOS;
1383   case Triple::DriverKit:
1384     return MachO::PLATFORM_DRIVERKIT;
1385   case Triple::XROS:
1386     return Target.isSimulatorEnvironment() ? MachO::PLATFORM_XROS_SIMULATOR
1387                                            : MachO::PLATFORM_XROS;
1388   default:
1389     break;
1390   }
1391   llvm_unreachable("unexpected OS type");
1392 }
1393
1394 void MCStreamer::emitVersionForTarget(
1395     const Triple &Target, const VersionTuple &SDKVersion,
1396     const Triple *DarwinTargetVariantTriple,
1397     const VersionTuple &DarwinTargetVariantSDKVersion) {
1398   if (!Target.isOSBinFormatMachO() || !Target.isOSDarwin())
1399     return;
1400   // Do we even know the version?
1401   if (Target.getOSMajorVersion() == 0)
1402     return;
1403
1404   VersionTuple Version;
1405   switch (Target.getOS()) {
1406   case Triple::MacOSX:
1407   case Triple::Darwin:
1408     Target.getMacOSXVersion(Version);
1409     break;
1410   case Triple::IOS:
1411   case Triple::TvOS:
1412     Version = Target.getiOSVersion();
1413     break;
1414   case Triple::WatchOS:
1415     Version = Target.getWatchOSVersion();
1416     break;
1417   case Triple::DriverKit:
1418     Version = Target.getDriverKitVersion();
1419     break;
1420   case Triple::XROS:
1421     Version = Target.getOSVersion();
1422     break;
1423   default:
1424     llvm_unreachable("unexpected OS type");
1425   }
1426   assert(Version.getMajor() != 0 && "A non-zero major version is expected");
1427   auto LinkedTargetVersion =
1428       targetVersionOrMinimumSupportedOSVersion(Target, Version);
1429   auto BuildVersionOSVersion = getMachoBuildVersionSupportedOS(Target);
1430   bool ShouldEmitBuildVersion = false;
1431   if (BuildVersionOSVersion.empty() ||
1432       LinkedTargetVersion >= BuildVersionOSVersion) {
1433     if (Target.isMacCatalystEnvironment() && DarwinTargetVariantTriple &&
1434         DarwinTargetVariantTriple->isMacOSX()) {
1435       emitVersionForTarget(*DarwinTargetVariantTriple,
1436                            DarwinTargetVariantSDKVersion,
1437                            /*DarwinTargetVariantTriple=*/nullptr,
1438                            /*DarwinTargetVariantSDKVersion=*/VersionTuple());
1439       emitDarwinTargetVariantBuildVersion(
1440           getMachoBuildVersionPlatformType(Target),
1441           LinkedTargetVersion.getMajor(),
1442           LinkedTargetVersion.getMinor().value_or(0),
1443           LinkedTargetVersion.getSubminor().value_or(0), SDKVersion);
1444       return;
1445     }
1446     emitBuildVersion(getMachoBuildVersionPlatformType(Target),
1447                      LinkedTargetVersion.getMajor(),
1448                      LinkedTargetVersion.getMinor().value_or(0),
1449                      LinkedTargetVersion.getSubminor().value_or(0), SDKVersion);
1450     ShouldEmitBuildVersion = true;
1451   }
1452
1453   if (const Triple *TVT = DarwinTargetVariantTriple) {
1454     if (Target.isMacOSX() && TVT->isMacCatalystEnvironment()) {
1455       auto TVLinkedTargetVersion =
1456           targetVersionOrMinimumSupportedOSVersion(*TVT, TVT->getiOSVersion());
1457       emitDarwinTargetVariantBuildVersion(
1458           getMachoBuildVersionPlatformType(*TVT),
1459           TVLinkedTargetVersion.getMajor(),
1460           TVLinkedTargetVersion.getMinor().value_or(0),
1461           TVLinkedTargetVersion.getSubminor().value_or(0),
1462           DarwinTargetVariantSDKVersion);
1463     }
1464   }
1465
1466   if (ShouldEmitBuildVersion)
1467     return;
1468
1469   emitVersionMin(getMachoVersionMinLoadCommandType(Target),
1470                  LinkedTargetVersion.getMajor(),
1471                  LinkedTargetVersion.getMinor().value_or(0),
1472                  LinkedTargetVersion.getSubminor().value_or(0), SDKVersion);
1473 }