llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp

   1 //===- DWARFDebugFrame.h - Parsing of .debug_frame ------------------------===//
   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/DebugInfo/DWARF/DWARFDebugFrame.h"
  10 #include "llvm/ADT/DenseMap.h"
  11 #include "llvm/ADT/Optional.h"
  12 #include "llvm/ADT/StringExtras.h"
  13 #include "llvm/ADT/StringRef.h"
  14 #include "llvm/BinaryFormat/Dwarf.h"
  15 #include "llvm/MC/MCRegisterInfo.h"
  16 #include "llvm/Support/Casting.h"
  17 #include "llvm/Support/Compiler.h"
  18 #include "llvm/Support/DataExtractor.h"
  19 #include "llvm/Support/Errc.h"
  20 #include "llvm/Support/ErrorHandling.h"
  21 #include "llvm/Support/Format.h"
  22 #include "llvm/Support/raw_ostream.h"
  23 #include <algorithm>
  24 #include <cassert>
  25 #include <cinttypes>
  26 #include <cstdint>
  27
  28 using namespace llvm;
  29 using namespace dwarf;
  30
  31 static void printRegister(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH,
  32                           unsigned RegNum) {
  33   if (MRI) {
  34     if (Optional<unsigned> LLVMRegNum = MRI->getLLVMRegNum(RegNum, IsEH)) {
  35       if (const char *RegName = MRI->getName(*LLVMRegNum)) {
  36         OS << RegName;
  37         return;
  38       }
  39     }
  40   }
  41   OS << "reg" << RegNum;
  42 }
  43
  44 UnwindLocation UnwindLocation::createUnspecified() { return {Unspecified}; }
  45
  46 UnwindLocation UnwindLocation::createUndefined() { return {Undefined}; }
  47
  48 UnwindLocation UnwindLocation::createSame() { return {Same}; }
  49
  50 UnwindLocation UnwindLocation::createIsConstant(int32_t Value) {
  51   return {Constant, InvalidRegisterNumber, Value, None, false};
  52 }
  53
  54 UnwindLocation UnwindLocation::createIsCFAPlusOffset(int32_t Offset) {
  55   return {CFAPlusOffset, InvalidRegisterNumber, Offset, None, false};
  56 }
  57
  58 UnwindLocation UnwindLocation::createAtCFAPlusOffset(int32_t Offset) {
  59   return {CFAPlusOffset, InvalidRegisterNumber, Offset, None, true};
  60 }
  61
  62 UnwindLocation
  63 UnwindLocation::createIsRegisterPlusOffset(uint32_t RegNum, int32_t Offset,
  64                                            Optional<uint32_t> AddrSpace) {
  65   return {RegPlusOffset, RegNum, Offset, AddrSpace, false};
  66 }
  67
  68 UnwindLocation
  69 UnwindLocation::createAtRegisterPlusOffset(uint32_t RegNum, int32_t Offset,
  70                                            Optional<uint32_t> AddrSpace) {
  71   return {RegPlusOffset, RegNum, Offset, AddrSpace, true};
  72 }
  73
  74 UnwindLocation UnwindLocation::createIsDWARFExpression(DWARFExpression Expr) {
  75   return {Expr, false};
  76 }
  77
  78 UnwindLocation UnwindLocation::createAtDWARFExpression(DWARFExpression Expr) {
  79   return {Expr, true};
  80 }
  81
  82 void UnwindLocation::dump(raw_ostream &OS, const MCRegisterInfo *MRI,
  83                           bool IsEH) const {
  84   if (Dereference)
  85     OS << '[';
  86   switch (Kind) {
  87   case Unspecified:
  88     OS << "unspecified";
  89     break;
  90   case Undefined:
  91     OS << "undefined";
  92     break;
  93   case Same:
  94     OS << "same";
  95     break;
  96   case CFAPlusOffset:
  97     OS << "CFA";
  98     if (Offset == 0)
  99       break;
 100     if (Offset > 0)
 101       OS << "+";
 102     OS << Offset;
 103     break;
 104   case RegPlusOffset:
 105     printRegister(OS, MRI, IsEH, RegNum);
 106     if (Offset == 0 && !AddrSpace)
 107       break;
 108     if (Offset >= 0)
 109       OS << "+";
 110     OS << Offset;
 111     if (AddrSpace)
 112       OS << " in addrspace" << *AddrSpace;
 113     break;
 114   case DWARFExpr:
 115     Expr->print(OS, DIDumpOptions(), MRI, nullptr, IsEH);
 116     break;
 117   case Constant:
 118     OS << Offset;
 119     break;
 120   }
 121   if (Dereference)
 122     OS << ']';
 123 }
 124
 125 raw_ostream &llvm::dwarf::operator<<(raw_ostream &OS,
 126                                      const UnwindLocation &UL) {
 127   UL.dump(OS, nullptr, false);
 128   return OS;
 129 }
 130
 131 bool UnwindLocation::operator==(const UnwindLocation &RHS) const {
 132   if (Kind != RHS.Kind)
 133     return false;
 134   switch (Kind) {
 135   case Unspecified:
 136   case Undefined:
 137   case Same:
 138     return true;
 139   case CFAPlusOffset:
 140     return Offset == RHS.Offset && Dereference == RHS.Dereference;
 141   case RegPlusOffset:
 142     return RegNum == RHS.RegNum && Offset == RHS.Offset &&
 143            Dereference == RHS.Dereference;
 144   case DWARFExpr:
 145     return *Expr == *RHS.Expr && Dereference == RHS.Dereference;
 146   case Constant:
 147     return Offset == RHS.Offset;
 148   }
 149   return false;
 150 }
 151
 152 void RegisterLocations::dump(raw_ostream &OS, const MCRegisterInfo *MRI,
 153                              bool IsEH) const {
 154   bool First = true;
 155   for (const auto &RegLocPair : Locations) {
 156     if (First)
 157       First = false;
 158     else
 159       OS << ", ";
 160     printRegister(OS, MRI, IsEH, RegLocPair.first);
 161     OS << '=';
 162     RegLocPair.second.dump(OS, MRI, IsEH);
 163   }
 164 }
 165
 166 raw_ostream &llvm::dwarf::operator<<(raw_ostream &OS,
 167                                      const RegisterLocations &RL) {
 168   RL.dump(OS, nullptr, false);
 169   return OS;
 170 }
 171
 172 void UnwindRow::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH,
 173                      unsigned IndentLevel) const {
 174   OS.indent(2 * IndentLevel);
 175   if (hasAddress())
 176     OS << format("0x%" PRIx64 ": ", *Address);
 177   OS << "CFA=";
 178   CFAValue.dump(OS, MRI, IsEH);
 179   if (RegLocs.hasLocations()) {
 180     OS << ": ";
 181     RegLocs.dump(OS, MRI, IsEH);
 182   }
 183   OS << "\n";
 184 }
 185
 186 raw_ostream &llvm::dwarf::operator<<(raw_ostream &OS, const UnwindRow &Row) {
 187   Row.dump(OS, nullptr, false, 0);
 188   return OS;
 189 }
 190
 191 void UnwindTable::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH,
 192                        unsigned IndentLevel) const {
 193   for (const UnwindRow &Row : Rows)
 194     Row.dump(OS, MRI, IsEH, IndentLevel);
 195 }
 196
 197 raw_ostream &llvm::dwarf::operator<<(raw_ostream &OS, const UnwindTable &Rows) {
 198   Rows.dump(OS, nullptr, false, 0);
 199   return OS;
 200 }
 201
 202 Expected<UnwindTable> UnwindTable::create(const FDE *Fde) {
 203   const CIE *Cie = Fde->getLinkedCIE();
 204   if (Cie == nullptr)
 205     return createStringError(errc::invalid_argument,
 206                              "unable to get CIE for FDE at offset 0x%" PRIx64,
 207                              Fde->getOffset());
 208
 209   // Rows will be empty if there are no CFI instructions.
 210   if (Cie->cfis().empty() && Fde->cfis().empty())
 211     return UnwindTable();
 212
 213   UnwindTable UT;
 214   UnwindRow Row;
 215   Row.setAddress(Fde->getInitialLocation());
 216   UT.EndAddress = Fde->getInitialLocation() + Fde->getAddressRange();
 217   if (Error CieError = UT.parseRows(Cie->cfis(), Row, nullptr))
 218     return std::move(CieError);
 219   // We need to save the initial locations of registers from the CIE parsing
 220   // in case we run into DW_CFA_restore or DW_CFA_restore_extended opcodes.
 221   const RegisterLocations InitialLocs = Row.getRegisterLocations();
 222   if (Error FdeError = UT.parseRows(Fde->cfis(), Row, &InitialLocs))
 223     return std::move(FdeError);
 224   // May be all the CFI instructions were DW_CFA_nop amd Row becomes empty.
 225   // Do not add that to the unwind table.
 226   if (Row.getRegisterLocations().hasLocations() ||
 227       Row.getCFAValue().getLocation() != UnwindLocation::Unspecified)
 228     UT.Rows.push_back(Row);
 229   return UT;
 230 }
 231
 232 Expected<UnwindTable> UnwindTable::create(const CIE *Cie) {
 233   // Rows will be empty if there are no CFI instructions.
 234   if (Cie->cfis().empty())
 235     return UnwindTable();
 236
 237   UnwindTable UT;
 238   UnwindRow Row;
 239   if (Error CieError = UT.parseRows(Cie->cfis(), Row, nullptr))
 240     return std::move(CieError);
 241   // May be all the CFI instructions were DW_CFA_nop amd Row becomes empty.
 242   // Do not add that to the unwind table.
 243   if (Row.getRegisterLocations().hasLocations() ||
 244       Row.getCFAValue().getLocation() != UnwindLocation::Unspecified)
 245     UT.Rows.push_back(Row);
 246   return UT;
 247 }
 248
 249 // See DWARF standard v3, section 7.23
 250 const uint8_t DWARF_CFI_PRIMARY_OPCODE_MASK = 0xc0;
 251 const uint8_t DWARF_CFI_PRIMARY_OPERAND_MASK = 0x3f;
 252
 253 Error CFIProgram::parse(DWARFDataExtractor Data, uint64_t *Offset,
 254                         uint64_t EndOffset) {
 255   DataExtractor::Cursor C(*Offset);
 256   while (C && C.tell() < EndOffset) {
 257     uint8_t Opcode = Data.getRelocatedValue(C, 1);
 258     if (!C)
 259       break;
 260
 261     // Some instructions have a primary opcode encoded in the top bits.
 262     if (uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK) {
 263       // If it's a primary opcode, the first operand is encoded in the bottom
 264       // bits of the opcode itself.
 265       uint64_t Op1 = Opcode & DWARF_CFI_PRIMARY_OPERAND_MASK;
 266       switch (Primary) {
 267       case DW_CFA_advance_loc:
 268       case DW_CFA_restore:
 269         addInstruction(Primary, Op1);
 270         break;
 271       case DW_CFA_offset:
 272         addInstruction(Primary, Op1, Data.getULEB128(C));
 273         break;
 274       default:
 275         llvm_unreachable("invalid primary CFI opcode");
 276       }
 277       continue;
 278     }
 279
 280     // Extended opcode - its value is Opcode itself.
 281     switch (Opcode) {
 282     default:
 283       return createStringError(errc::illegal_byte_sequence,
 284                                "invalid extended CFI opcode 0x%" PRIx8, Opcode);
 285     case DW_CFA_nop:
 286     case DW_CFA_remember_state:
 287     case DW_CFA_restore_state:
 288     case DW_CFA_GNU_window_save:
 289       // No operands
 290       addInstruction(Opcode);
 291       break;
 292     case DW_CFA_set_loc:
 293       // Operands: Address
 294       addInstruction(Opcode, Data.getRelocatedAddress(C));
 295       break;
 296     case DW_CFA_advance_loc1:
 297       // Operands: 1-byte delta
 298       addInstruction(Opcode, Data.getRelocatedValue(C, 1));
 299       break;
 300     case DW_CFA_advance_loc2:
 301       // Operands: 2-byte delta
 302       addInstruction(Opcode, Data.getRelocatedValue(C, 2));
 303       break;
 304     case DW_CFA_advance_loc4:
 305       // Operands: 4-byte delta
 306       addInstruction(Opcode, Data.getRelocatedValue(C, 4));
 307       break;
 308     case DW_CFA_restore_extended:
 309     case DW_CFA_undefined:
 310     case DW_CFA_same_value:
 311     case DW_CFA_def_cfa_register:
 312     case DW_CFA_def_cfa_offset:
 313     case DW_CFA_GNU_args_size:
 314       // Operands: ULEB128
 315       addInstruction(Opcode, Data.getULEB128(C));
 316       break;
 317     case DW_CFA_def_cfa_offset_sf:
 318       // Operands: SLEB128
 319       addInstruction(Opcode, Data.getSLEB128(C));
 320       break;
 321     case DW_CFA_LLVM_def_aspace_cfa:
 322     case DW_CFA_LLVM_def_aspace_cfa_sf: {
 323       auto RegNum = Data.getULEB128(C);
 324       auto CfaOffset = Opcode == DW_CFA_LLVM_def_aspace_cfa
 325                            ? Data.getULEB128(C)
 326                            : Data.getSLEB128(C);
 327       auto AddressSpace = Data.getULEB128(C);
 328       addInstruction(Opcode, RegNum, CfaOffset, AddressSpace);
 329       break;
 330     }
 331     case DW_CFA_offset_extended:
 332     case DW_CFA_register:
 333     case DW_CFA_def_cfa:
 334     case DW_CFA_val_offset: {
 335       // Operands: ULEB128, ULEB128
 336       // Note: We can not embed getULEB128 directly into function
 337       // argument list. getULEB128 changes Offset and order of evaluation
 338       // for arguments is unspecified.
 339       uint64_t op1 = Data.getULEB128(C);
 340       uint64_t op2 = Data.getULEB128(C);
 341       addInstruction(Opcode, op1, op2);
 342       break;
 343     }
 344     case DW_CFA_offset_extended_sf:
 345     case DW_CFA_def_cfa_sf:
 346     case DW_CFA_val_offset_sf: {
 347       // Operands: ULEB128, SLEB128
 348       // Note: see comment for the previous case
 349       uint64_t op1 = Data.getULEB128(C);
 350       uint64_t op2 = (uint64_t)Data.getSLEB128(C);
 351       addInstruction(Opcode, op1, op2);
 352       break;
 353     }
 354     case DW_CFA_def_cfa_expression: {
 355       uint64_t ExprLength = Data.getULEB128(C);
 356       addInstruction(Opcode, 0);
 357       StringRef Expression = Data.getBytes(C, ExprLength);
 358
 359       DataExtractor Extractor(Expression, Data.isLittleEndian(),
 360                               Data.getAddressSize());
 361       // Note. We do not pass the DWARF format to DWARFExpression, because
 362       // DW_OP_call_ref, the only operation which depends on the format, is
 363       // prohibited in call frame instructions, see sec. 6.4.2 in DWARFv5.
 364       Instructions.back().Expression =
 365           DWARFExpression(Extractor, Data.getAddressSize());
 366       break;
 367     }
 368     case DW_CFA_expression:
 369     case DW_CFA_val_expression: {
 370       uint64_t RegNum = Data.getULEB128(C);
 371       addInstruction(Opcode, RegNum, 0);
 372
 373       uint64_t BlockLength = Data.getULEB128(C);
 374       StringRef Expression = Data.getBytes(C, BlockLength);
 375       DataExtractor Extractor(Expression, Data.isLittleEndian(),
 376                               Data.getAddressSize());
 377       // Note. We do not pass the DWARF format to DWARFExpression, because
 378       // DW_OP_call_ref, the only operation which depends on the format, is
 379       // prohibited in call frame instructions, see sec. 6.4.2 in DWARFv5.
 380       Instructions.back().Expression =
 381           DWARFExpression(Extractor, Data.getAddressSize());
 382       break;
 383     }
 384     }
 385   }
 386
 387   *Offset = C.tell();
 388   return C.takeError();
 389 }
 390
 391 StringRef CFIProgram::callFrameString(unsigned Opcode) const {
 392   return dwarf::CallFrameString(Opcode, Arch);
 393 }
 394
 395 const char *CFIProgram::operandTypeString(CFIProgram::OperandType OT) {
 396 #define ENUM_TO_CSTR(e)                                                        \
 397   case e:                                                                      \
 398     return #e;
 399   switch (OT) {
 400     ENUM_TO_CSTR(OT_Unset);
 401     ENUM_TO_CSTR(OT_None);
 402     ENUM_TO_CSTR(OT_Address);
 403     ENUM_TO_CSTR(OT_Offset);
 404     ENUM_TO_CSTR(OT_FactoredCodeOffset);
 405     ENUM_TO_CSTR(OT_SignedFactDataOffset);
 406     ENUM_TO_CSTR(OT_UnsignedFactDataOffset);
 407     ENUM_TO_CSTR(OT_Register);
 408     ENUM_TO_CSTR(OT_AddressSpace);
 409     ENUM_TO_CSTR(OT_Expression);
 410   }
 411   return "<unknown CFIProgram::OperandType>";
 412 }
 413
 414 llvm::Expected<uint64_t>
 415 CFIProgram::Instruction::getOperandAsUnsigned(const CFIProgram &CFIP,
 416                                               uint32_t OperandIdx) const {
 417   if (OperandIdx >= MaxOperands)
 418     return createStringError(errc::invalid_argument,
 419                              "operand index %" PRIu32 " is not valid",
 420                              OperandIdx);
 421   OperandType Type = CFIP.getOperandTypes()[Opcode][OperandIdx];
 422   uint64_t Operand = Ops[OperandIdx];
 423   switch (Type) {
 424   case OT_Unset:
 425   case OT_None:
 426   case OT_Expression:
 427     return createStringError(errc::invalid_argument,
 428                              "op[%" PRIu32 "] has type %s which has no value",
 429                              OperandIdx, CFIProgram::operandTypeString(Type));
 430
 431   case OT_Offset:
 432   case OT_SignedFactDataOffset:
 433   case OT_UnsignedFactDataOffset:
 434     return createStringError(
 435         errc::invalid_argument,
 436         "op[%" PRIu32 "] has OperandType OT_Offset which produces a signed "
 437         "result, call getOperandAsSigned instead",
 438         OperandIdx);
 439
 440   case OT_Address:
 441   case OT_Register:
 442   case OT_AddressSpace:
 443     return Operand;
 444
 445   case OT_FactoredCodeOffset: {
 446     const uint64_t CodeAlignmentFactor = CFIP.codeAlign();
 447     if (CodeAlignmentFactor == 0)
 448       return createStringError(
 449           errc::invalid_argument,
 450           "op[%" PRIu32 "] has type OT_FactoredCodeOffset but code alignment "
 451           "is zero",
 452           OperandIdx);
 453     return Operand * CodeAlignmentFactor;
 454   }
 455   }
 456   llvm_unreachable("invalid operand type");
 457 }
 458
 459 llvm::Expected<int64_t>
 460 CFIProgram::Instruction::getOperandAsSigned(const CFIProgram &CFIP,
 461                                             uint32_t OperandIdx) const {
 462   if (OperandIdx >= MaxOperands)
 463     return createStringError(errc::invalid_argument,
 464                              "operand index %" PRIu32 " is not valid",
 465                              OperandIdx);
 466   OperandType Type = CFIP.getOperandTypes()[Opcode][OperandIdx];
 467   uint64_t Operand = Ops[OperandIdx];
 468   switch (Type) {
 469   case OT_Unset:
 470   case OT_None:
 471   case OT_Expression:
 472     return createStringError(errc::invalid_argument,
 473                              "op[%" PRIu32 "] has type %s which has no value",
 474                              OperandIdx, CFIProgram::operandTypeString(Type));
 475
 476   case OT_Address:
 477   case OT_Register:
 478   case OT_AddressSpace:
 479     return createStringError(
 480         errc::invalid_argument,
 481         "op[%" PRIu32 "] has OperandType %s which produces an unsigned result, "
 482         "call getOperandAsUnsigned instead",
 483         OperandIdx, CFIProgram::operandTypeString(Type));
 484
 485   case OT_Offset:
 486     return (int64_t)Operand;
 487
 488   case OT_FactoredCodeOffset:
 489   case OT_SignedFactDataOffset: {
 490     const int64_t DataAlignmentFactor = CFIP.dataAlign();
 491     if (DataAlignmentFactor == 0)
 492       return createStringError(errc::invalid_argument,
 493                                "op[%" PRIu32 "] has type %s but data "
 494                                "alignment is zero",
 495                                OperandIdx, CFIProgram::operandTypeString(Type));
 496     return int64_t(Operand) * DataAlignmentFactor;
 497   }
 498
 499   case OT_UnsignedFactDataOffset: {
 500     const int64_t DataAlignmentFactor = CFIP.dataAlign();
 501     if (DataAlignmentFactor == 0)
 502       return createStringError(errc::invalid_argument,
 503                                "op[%" PRIu32
 504                                "] has type OT_UnsignedFactDataOffset but data "
 505                                "alignment is zero",
 506                                OperandIdx);
 507     return Operand * DataAlignmentFactor;
 508   }
 509   }
 510   llvm_unreachable("invalid operand type");
 511 }
 512
 513 Error UnwindTable::parseRows(const CFIProgram &CFIP, UnwindRow &Row,
 514                              const RegisterLocations *InitialLocs) {
 515   std::vector<RegisterLocations> RegisterStates;
 516   for (const CFIProgram::Instruction &Inst : CFIP) {
 517     switch (Inst.Opcode) {
 518     case dwarf::DW_CFA_set_loc: {
 519       // The DW_CFA_set_loc instruction takes a single operand that
 520       // represents a target address. The required action is to create a new
 521       // table row using the specified address as the location. All other
 522       // values in the new row are initially identical to the current row.
 523       // The new location value is always greater than the current one. If
 524       // the segment_size field of this FDE's CIE is non- zero, the initial
 525       // location is preceded by a segment selector of the given length
 526       llvm::Expected<uint64_t> NewAddress = Inst.getOperandAsUnsigned(CFIP, 0);
 527       if (!NewAddress)
 528         return NewAddress.takeError();
 529       if (*NewAddress <= Row.getAddress())
 530         return createStringError(
 531             errc::invalid_argument,
 532             "%s with adrress 0x%" PRIx64 " which must be greater than the "
 533             "current row address 0x%" PRIx64,
 534             CFIP.callFrameString(Inst.Opcode).str().c_str(), *NewAddress,
 535             Row.getAddress());
 536       Rows.push_back(Row);
 537       Row.setAddress(*NewAddress);
 538       break;
 539     }
 540
 541     case dwarf::DW_CFA_advance_loc:
 542     case dwarf::DW_CFA_advance_loc1:
 543     case dwarf::DW_CFA_advance_loc2:
 544     case dwarf::DW_CFA_advance_loc4: {
 545       // The DW_CFA_advance instruction takes a single operand that
 546       // represents a constant delta. The required action is to create a new
 547       // table row with a location value that is computed by taking the
 548       // current entry’s location value and adding the value of delta *
 549       // code_alignment_factor. All other values in the new row are initially
 550       // identical to the current row.
 551       Rows.push_back(Row);
 552       llvm::Expected<uint64_t> Offset = Inst.getOperandAsUnsigned(CFIP, 0);
 553       if (!Offset)
 554         return Offset.takeError();
 555       Row.slideAddress(*Offset);
 556       break;
 557     }
 558
 559     case dwarf::DW_CFA_restore:
 560     case dwarf::DW_CFA_restore_extended: {
 561       // The DW_CFA_restore instruction takes a single operand (encoded with
 562       // the opcode) that represents a register number. The required action
 563       // is to change the rule for the indicated register to the rule
 564       // assigned it by the initial_instructions in the CIE.
 565       if (InitialLocs == nullptr)
 566         return createStringError(
 567             errc::invalid_argument, "%s encountered while parsing a CIE",
 568             CFIP.callFrameString(Inst.Opcode).str().c_str());
 569       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 570       if (!RegNum)
 571         return RegNum.takeError();
 572       if (Optional<UnwindLocation> O =
 573               InitialLocs->getRegisterLocation(*RegNum))
 574         Row.getRegisterLocations().setRegisterLocation(*RegNum, *O);
 575       else
 576         Row.getRegisterLocations().removeRegisterLocation(*RegNum);
 577       break;
 578     }
 579
 580     case dwarf::DW_CFA_offset:
 581     case dwarf::DW_CFA_offset_extended:
 582     case dwarf::DW_CFA_offset_extended_sf: {
 583       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 584       if (!RegNum)
 585         return RegNum.takeError();
 586       llvm::Expected<int64_t> Offset = Inst.getOperandAsSigned(CFIP, 1);
 587       if (!Offset)
 588         return Offset.takeError();
 589       Row.getRegisterLocations().setRegisterLocation(
 590           *RegNum, UnwindLocation::createAtCFAPlusOffset(*Offset));
 591       break;
 592     }
 593
 594     case dwarf::DW_CFA_nop:
 595       break;
 596
 597     case dwarf::DW_CFA_remember_state:
 598       RegisterStates.push_back(Row.getRegisterLocations());
 599       break;
 600
 601     case dwarf::DW_CFA_restore_state:
 602       if (RegisterStates.empty())
 603         return createStringError(errc::invalid_argument,
 604                                  "DW_CFA_restore_state without a matching "
 605                                  "previous DW_CFA_remember_state");
 606       Row.getRegisterLocations() = RegisterStates.back();
 607       RegisterStates.pop_back();
 608       break;
 609
 610     case dwarf::DW_CFA_GNU_window_save:
 611       switch (CFIP.triple()) {
 612       case Triple::aarch64:
 613       case Triple::aarch64_be:
 614       case Triple::aarch64_32: {
 615         // DW_CFA_GNU_window_save is used for different things on different
 616         // architectures. For aarch64 it is known as
 617         // DW_CFA_AARCH64_negate_ra_state. The action is to toggle the
 618         // value of the return address state between 1 and 0. If there is
 619         // no rule for the AARCH64_DWARF_PAUTH_RA_STATE register, then it
 620         // should be initially set to 1.
 621         constexpr uint32_t AArch64DWARFPAuthRaState = 34;
 622         auto LRLoc = Row.getRegisterLocations().getRegisterLocation(
 623             AArch64DWARFPAuthRaState);
 624         if (LRLoc) {
 625           if (LRLoc->getLocation() == UnwindLocation::Constant) {
 626             // Toggle the constant value from 0 to 1 or 1 to 0.
 627             LRLoc->setConstant(LRLoc->getConstant() ^ 1);
 628           } else {
 629             return createStringError(
 630                 errc::invalid_argument,
 631                 "%s encountered when existing rule for this register is not "
 632                 "a constant",
 633                 CFIP.callFrameString(Inst.Opcode).str().c_str());
 634           }
 635         } else {
 636           Row.getRegisterLocations().setRegisterLocation(
 637               AArch64DWARFPAuthRaState, UnwindLocation::createIsConstant(1));
 638         }
 639         break;
 640       }
 641
 642       case Triple::sparc:
 643       case Triple::sparcv9:
 644       case Triple::sparcel:
 645         for (uint32_t RegNum = 16; RegNum < 32; ++RegNum) {
 646           Row.getRegisterLocations().setRegisterLocation(
 647               RegNum, UnwindLocation::createAtCFAPlusOffset((RegNum - 16) * 8));
 648         }
 649         break;
 650
 651       default: {
 652         return createStringError(
 653             errc::not_supported,
 654             "DW_CFA opcode %#x is not supported for architecture %s",
 655             Inst.Opcode, Triple::getArchTypeName(CFIP.triple()).str().c_str());
 656
 657         break;
 658       }
 659       }
 660       break;
 661
 662     case dwarf::DW_CFA_undefined: {
 663       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 664       if (!RegNum)
 665         return RegNum.takeError();
 666       Row.getRegisterLocations().setRegisterLocation(
 667           *RegNum, UnwindLocation::createUndefined());
 668       break;
 669     }
 670
 671     case dwarf::DW_CFA_same_value: {
 672       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 673       if (!RegNum)
 674         return RegNum.takeError();
 675       Row.getRegisterLocations().setRegisterLocation(
 676           *RegNum, UnwindLocation::createSame());
 677       break;
 678     }
 679
 680     case dwarf::DW_CFA_GNU_args_size:
 681       break;
 682
 683     case dwarf::DW_CFA_register: {
 684       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 685       if (!RegNum)
 686         return RegNum.takeError();
 687       llvm::Expected<uint64_t> NewRegNum = Inst.getOperandAsUnsigned(CFIP, 1);
 688       if (!NewRegNum)
 689         return NewRegNum.takeError();
 690       Row.getRegisterLocations().setRegisterLocation(
 691           *RegNum, UnwindLocation::createIsRegisterPlusOffset(*NewRegNum, 0));
 692       break;
 693     }
 694
 695     case dwarf::DW_CFA_val_offset:
 696     case dwarf::DW_CFA_val_offset_sf: {
 697       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 698       if (!RegNum)
 699         return RegNum.takeError();
 700       llvm::Expected<int64_t> Offset = Inst.getOperandAsSigned(CFIP, 1);
 701       if (!Offset)
 702         return Offset.takeError();
 703       Row.getRegisterLocations().setRegisterLocation(
 704           *RegNum, UnwindLocation::createIsCFAPlusOffset(*Offset));
 705       break;
 706     }
 707
 708     case dwarf::DW_CFA_expression: {
 709       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 710       if (!RegNum)
 711         return RegNum.takeError();
 712       Row.getRegisterLocations().setRegisterLocation(
 713           *RegNum, UnwindLocation::createAtDWARFExpression(*Inst.Expression));
 714       break;
 715     }
 716
 717     case dwarf::DW_CFA_val_expression: {
 718       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 719       if (!RegNum)
 720         return RegNum.takeError();
 721       Row.getRegisterLocations().setRegisterLocation(
 722           *RegNum, UnwindLocation::createIsDWARFExpression(*Inst.Expression));
 723       break;
 724     }
 725
 726     case dwarf::DW_CFA_def_cfa_register: {
 727       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 728       if (!RegNum)
 729         return RegNum.takeError();
 730       if (Row.getCFAValue().getLocation() != UnwindLocation::RegPlusOffset)
 731         Row.getCFAValue() =
 732             UnwindLocation::createIsRegisterPlusOffset(*RegNum, 0);
 733       else
 734         Row.getCFAValue().setRegister(*RegNum);
 735       break;
 736     }
 737
 738     case dwarf::DW_CFA_def_cfa_offset:
 739     case dwarf::DW_CFA_def_cfa_offset_sf: {
 740       llvm::Expected<int64_t> Offset = Inst.getOperandAsSigned(CFIP, 0);
 741       if (!Offset)
 742         return Offset.takeError();
 743       if (Row.getCFAValue().getLocation() != UnwindLocation::RegPlusOffset) {
 744         return createStringError(
 745             errc::invalid_argument,
 746             "%s found when CFA rule was not RegPlusOffset",
 747             CFIP.callFrameString(Inst.Opcode).str().c_str());
 748       }
 749       Row.getCFAValue().setOffset(*Offset);
 750       break;
 751     }
 752
 753     case dwarf::DW_CFA_def_cfa:
 754     case dwarf::DW_CFA_def_cfa_sf: {
 755       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 756       if (!RegNum)
 757         return RegNum.takeError();
 758       llvm::Expected<int64_t> Offset = Inst.getOperandAsSigned(CFIP, 1);
 759       if (!Offset)
 760         return Offset.takeError();
 761       Row.getCFAValue() =
 762           UnwindLocation::createIsRegisterPlusOffset(*RegNum, *Offset);
 763       break;
 764     }
 765
 766     case dwarf::DW_CFA_LLVM_def_aspace_cfa:
 767     case dwarf::DW_CFA_LLVM_def_aspace_cfa_sf: {
 768       llvm::Expected<uint64_t> RegNum = Inst.getOperandAsUnsigned(CFIP, 0);
 769       if (!RegNum)
 770         return RegNum.takeError();
 771       llvm::Expected<int64_t> Offset = Inst.getOperandAsSigned(CFIP, 1);
 772       if (!Offset)
 773         return Offset.takeError();
 774       llvm::Expected<uint32_t> CFAAddrSpace =
 775           Inst.getOperandAsUnsigned(CFIP, 2);
 776       if (!CFAAddrSpace)
 777         return CFAAddrSpace.takeError();
 778       Row.getCFAValue() = UnwindLocation::createIsRegisterPlusOffset(
 779           *RegNum, *Offset, *CFAAddrSpace);
 780       break;
 781     }
 782
 783     case dwarf::DW_CFA_def_cfa_expression:
 784       Row.getCFAValue() =
 785           UnwindLocation::createIsDWARFExpression(*Inst.Expression);
 786       break;
 787     }
 788   }
 789   return Error::success();
 790 }
 791
 792 ArrayRef<CFIProgram::OperandType[CFIProgram::MaxOperands]>
 793 CFIProgram::getOperandTypes() {
 794   static OperandType OpTypes[DW_CFA_restore + 1][MaxOperands];
 795   static bool Initialized = false;
 796   if (Initialized) {
 797     return ArrayRef<OperandType[MaxOperands]>(&OpTypes[0], DW_CFA_restore + 1);
 798   }
 799   Initialized = true;
 800
 801 #define DECLARE_OP3(OP, OPTYPE0, OPTYPE1, OPTYPE2)                             \
 802   do {                                                                         \
 803     OpTypes[OP][0] = OPTYPE0;                                                  \
 804     OpTypes[OP][1] = OPTYPE1;                                                  \
 805     OpTypes[OP][2] = OPTYPE2;                                                  \
 806   } while (false)
 807 #define DECLARE_OP2(OP, OPTYPE0, OPTYPE1)                                      \
 808   DECLARE_OP3(OP, OPTYPE0, OPTYPE1, OT_None)
 809 #define DECLARE_OP1(OP, OPTYPE0) DECLARE_OP2(OP, OPTYPE0, OT_None)
 810 #define DECLARE_OP0(OP) DECLARE_OP1(OP, OT_None)
 811
 812   DECLARE_OP1(DW_CFA_set_loc, OT_Address);
 813   DECLARE_OP1(DW_CFA_advance_loc, OT_FactoredCodeOffset);
 814   DECLARE_OP1(DW_CFA_advance_loc1, OT_FactoredCodeOffset);
 815   DECLARE_OP1(DW_CFA_advance_loc2, OT_FactoredCodeOffset);
 816   DECLARE_OP1(DW_CFA_advance_loc4, OT_FactoredCodeOffset);
 817   DECLARE_OP1(DW_CFA_MIPS_advance_loc8, OT_FactoredCodeOffset);
 818   DECLARE_OP2(DW_CFA_def_cfa, OT_Register, OT_Offset);
 819   DECLARE_OP2(DW_CFA_def_cfa_sf, OT_Register, OT_SignedFactDataOffset);
 820   DECLARE_OP1(DW_CFA_def_cfa_register, OT_Register);
 821   DECLARE_OP3(DW_CFA_LLVM_def_aspace_cfa, OT_Register, OT_Offset,
 822               OT_AddressSpace);
 823   DECLARE_OP3(DW_CFA_LLVM_def_aspace_cfa_sf, OT_Register,
 824               OT_SignedFactDataOffset, OT_AddressSpace);
 825   DECLARE_OP1(DW_CFA_def_cfa_offset, OT_Offset);
 826   DECLARE_OP1(DW_CFA_def_cfa_offset_sf, OT_SignedFactDataOffset);
 827   DECLARE_OP1(DW_CFA_def_cfa_expression, OT_Expression);
 828   DECLARE_OP1(DW_CFA_undefined, OT_Register);
 829   DECLARE_OP1(DW_CFA_same_value, OT_Register);
 830   DECLARE_OP2(DW_CFA_offset, OT_Register, OT_UnsignedFactDataOffset);
 831   DECLARE_OP2(DW_CFA_offset_extended, OT_Register, OT_UnsignedFactDataOffset);
 832   DECLARE_OP2(DW_CFA_offset_extended_sf, OT_Register, OT_SignedFactDataOffset);
 833   DECLARE_OP2(DW_CFA_val_offset, OT_Register, OT_UnsignedFactDataOffset);
 834   DECLARE_OP2(DW_CFA_val_offset_sf, OT_Register, OT_SignedFactDataOffset);
 835   DECLARE_OP2(DW_CFA_register, OT_Register, OT_Register);
 836   DECLARE_OP2(DW_CFA_expression, OT_Register, OT_Expression);
 837   DECLARE_OP2(DW_CFA_val_expression, OT_Register, OT_Expression);
 838   DECLARE_OP1(DW_CFA_restore, OT_Register);
 839   DECLARE_OP1(DW_CFA_restore_extended, OT_Register);
 840   DECLARE_OP0(DW_CFA_remember_state);
 841   DECLARE_OP0(DW_CFA_restore_state);
 842   DECLARE_OP0(DW_CFA_GNU_window_save);
 843   DECLARE_OP1(DW_CFA_GNU_args_size, OT_Offset);
 844   DECLARE_OP0(DW_CFA_nop);
 845
 846 #undef DECLARE_OP0
 847 #undef DECLARE_OP1
 848 #undef DECLARE_OP2
 849
 850   return ArrayRef<OperandType[MaxOperands]>(&OpTypes[0], DW_CFA_restore + 1);
 851 }
 852
 853 /// Print \p Opcode's operand number \p OperandIdx which has value \p Operand.
 854 void CFIProgram::printOperand(raw_ostream &OS, DIDumpOptions DumpOpts,
 855                               const MCRegisterInfo *MRI, bool IsEH,
 856                               const Instruction &Instr, unsigned OperandIdx,
 857                               uint64_t Operand) const {
 858   assert(OperandIdx < MaxOperands);
 859   uint8_t Opcode = Instr.Opcode;
 860   OperandType Type = getOperandTypes()[Opcode][OperandIdx];
 861
 862   switch (Type) {
 863   case OT_Unset: {
 864     OS << " Unsupported " << (OperandIdx ? "second" : "first") << " operand to";
 865     auto OpcodeName = callFrameString(Opcode);
 866     if (!OpcodeName.empty())
 867       OS << " " << OpcodeName;
 868     else
 869       OS << format(" Opcode %x",  Opcode);
 870     break;
 871   }
 872   case OT_None:
 873     break;
 874   case OT_Address:
 875     OS << format(" %" PRIx64, Operand);
 876     break;
 877   case OT_Offset:
 878     // The offsets are all encoded in a unsigned form, but in practice
 879     // consumers use them signed. It's most certainly legacy due to
 880     // the lack of signed variants in the first Dwarf standards.
 881     OS << format(" %+" PRId64, int64_t(Operand));
 882     break;
 883   case OT_FactoredCodeOffset: // Always Unsigned
 884     if (CodeAlignmentFactor)
 885       OS << format(" %" PRId64, Operand * CodeAlignmentFactor);
 886     else
 887       OS << format(" %" PRId64 "*code_alignment_factor" , Operand);
 888     break;
 889   case OT_SignedFactDataOffset:
 890     if (DataAlignmentFactor)
 891       OS << format(" %" PRId64, int64_t(Operand) * DataAlignmentFactor);
 892     else
 893       OS << format(" %" PRId64 "*data_alignment_factor" , int64_t(Operand));
 894     break;
 895   case OT_UnsignedFactDataOffset:
 896     if (DataAlignmentFactor)
 897       OS << format(" %" PRId64, Operand * DataAlignmentFactor);
 898     else
 899       OS << format(" %" PRId64 "*data_alignment_factor" , Operand);
 900     break;
 901   case OT_Register:
 902     OS << ' ';
 903     printRegister(OS, MRI, IsEH, Operand);
 904     break;
 905   case OT_AddressSpace:
 906     OS << format(" in addrspace%" PRId64, Operand);
 907     break;
 908   case OT_Expression:
 909     assert(Instr.Expression && "missing DWARFExpression object");
 910     OS << " ";
 911     Instr.Expression->print(OS, DumpOpts, MRI, nullptr, IsEH);
 912     break;
 913   }
 914 }
 915
 916 void CFIProgram::dump(raw_ostream &OS, DIDumpOptions DumpOpts,
 917                       const MCRegisterInfo *MRI, bool IsEH,
 918                       unsigned IndentLevel) const {
 919   for (const auto &Instr : Instructions) {
 920     uint8_t Opcode = Instr.Opcode;
 921     OS.indent(2 * IndentLevel);
 922     OS << callFrameString(Opcode) << ":";
 923     for (unsigned i = 0; i < Instr.Ops.size(); ++i)
 924       printOperand(OS, DumpOpts, MRI, IsEH, Instr, i, Instr.Ops[i]);
 925     OS << '\n';
 926   }
 927 }
 928
 929 // Returns the CIE identifier to be used by the requested format.
 930 // CIE ids for .debug_frame sections are defined in Section 7.24 of DWARFv5.
 931 // For CIE ID in .eh_frame sections see
 932 // https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
 933 constexpr uint64_t getCIEId(bool IsDWARF64, bool IsEH) {
 934   if (IsEH)
 935     return 0;
 936   if (IsDWARF64)
 937     return DW64_CIE_ID;
 938   return DW_CIE_ID;
 939 }
 940
 941 void CIE::dump(raw_ostream &OS, DIDumpOptions DumpOpts,
 942                const MCRegisterInfo *MRI, bool IsEH) const {
 943   // A CIE with a zero length is a terminator entry in the .eh_frame section.
 944   if (IsEH && Length == 0) {
 945     OS << format("%08" PRIx64, Offset) << " ZERO terminator\n";
 946     return;
 947   }
 948
 949   OS << format("%08" PRIx64, Offset)
 950      << format(" %0*" PRIx64, IsDWARF64 ? 16 : 8, Length)
 951      << format(" %0*" PRIx64, IsDWARF64 && !IsEH ? 16 : 8,
 952                getCIEId(IsDWARF64, IsEH))
 953      << " CIE\n"
 954      << "  Format:                " << FormatString(IsDWARF64) << "\n";
 955   if (IsEH && Version != 1)
 956     OS << "WARNING: unsupported CIE version\n";
 957   OS << format("  Version:               %d\n", Version)
 958      << "  Augmentation:          \"" << Augmentation << "\"\n";
 959   if (Version >= 4) {
 960     OS << format("  Address size:          %u\n", (uint32_t)AddressSize);
 961     OS << format("  Segment desc size:     %u\n",
 962                  (uint32_t)SegmentDescriptorSize);
 963   }
 964   OS << format("  Code alignment factor: %u\n", (uint32_t)CodeAlignmentFactor);
 965   OS << format("  Data alignment factor: %d\n", (int32_t)DataAlignmentFactor);
 966   OS << format("  Return address column: %d\n", (int32_t)ReturnAddressRegister);
 967   if (Personality)
 968     OS << format("  Personality Address: %016" PRIx64 "\n", *Personality);
 969   if (!AugmentationData.empty()) {
 970     OS << "  Augmentation data:    ";
 971     for (uint8_t Byte : AugmentationData)
 972       OS << ' ' << hexdigit(Byte >> 4) << hexdigit(Byte & 0xf);
 973     OS << "\n";
 974   }
 975   OS << "\n";
 976   CFIs.dump(OS, DumpOpts, MRI, IsEH);
 977   OS << "\n";
 978
 979   if (Expected<UnwindTable> RowsOrErr = UnwindTable::create(this))
 980     RowsOrErr->dump(OS, MRI, IsEH, 1);
 981   else {
 982     DumpOpts.RecoverableErrorHandler(joinErrors(
 983         createStringError(errc::invalid_argument,
 984                           "decoding the CIE opcodes into rows failed"),
 985         RowsOrErr.takeError()));
 986   }
 987   OS << "\n";
 988 }
 989
 990 void FDE::dump(raw_ostream &OS, DIDumpOptions DumpOpts,
 991                const MCRegisterInfo *MRI, bool IsEH) const {
 992   OS << format("%08" PRIx64, Offset)
 993      << format(" %0*" PRIx64, IsDWARF64 ? 16 : 8, Length)
 994      << format(" %0*" PRIx64, IsDWARF64 && !IsEH ? 16 : 8, CIEPointer)
 995      << " FDE cie=";
 996   if (LinkedCIE)
 997     OS << format("%08" PRIx64, LinkedCIE->getOffset());
 998   else
 999     OS << "<invalid offset>";
1000   OS << format(" pc=%08" PRIx64 "...%08" PRIx64 "\n", InitialLocation,
1001                InitialLocation + AddressRange);
1002   OS << "  Format:       " << FormatString(IsDWARF64) << "\n";
1003   if (LSDAAddress)
1004     OS << format("  LSDA Address: %016" PRIx64 "\n", *LSDAAddress);
1005   CFIs.dump(OS, DumpOpts, MRI, IsEH);
1006   OS << "\n";
1007
1008   if (Expected<UnwindTable> RowsOrErr = UnwindTable::create(this))
1009     RowsOrErr->dump(OS, MRI, IsEH, 1);
1010   else {
1011     DumpOpts.RecoverableErrorHandler(joinErrors(
1012         createStringError(errc::invalid_argument,
1013                           "decoding the FDE opcodes into rows failed"),
1014         RowsOrErr.takeError()));
1015   }
1016   OS << "\n";
1017 }
1018
1019 DWARFDebugFrame::DWARFDebugFrame(Triple::ArchType Arch,
1020     bool IsEH, uint64_t EHFrameAddress)
1021     : Arch(Arch), IsEH(IsEH), EHFrameAddress(EHFrameAddress) {}
1022
1023 DWARFDebugFrame::~DWARFDebugFrame() = default;
1024
1025 static void LLVM_ATTRIBUTE_UNUSED dumpDataAux(DataExtractor Data,
1026                                               uint64_t Offset, int Length) {
1027   errs() << "DUMP: ";
1028   for (int i = 0; i < Length; ++i) {
1029     uint8_t c = Data.getU8(&Offset);
1030     errs().write_hex(c); errs() << " ";
1031   }
1032   errs() << "\n";
1033 }
1034
1035 Error DWARFDebugFrame::parse(DWARFDataExtractor Data) {
1036   uint64_t Offset = 0;
1037   DenseMap<uint64_t, CIE *> CIEs;
1038
1039   while (Data.isValidOffset(Offset)) {
1040     uint64_t StartOffset = Offset;
1041
1042     uint64_t Length;
1043     DwarfFormat Format;
1044     std::tie(Length, Format) = Data.getInitialLength(&Offset);
1045     bool IsDWARF64 = Format == DWARF64;
1046
1047     // If the Length is 0, then this CIE is a terminator. We add it because some
1048     // dumper tools might need it to print something special for such entries
1049     // (e.g. llvm-objdump --dwarf=frames prints "ZERO terminator").
1050     if (Length == 0) {
1051       auto Cie = std::make_unique<CIE>(
1052           IsDWARF64, StartOffset, 0, 0, SmallString<8>(), 0, 0, 0, 0, 0,
1053           SmallString<8>(), 0, 0, None, None, Arch);
1054       CIEs[StartOffset] = Cie.get();
1055       Entries.push_back(std::move(Cie));
1056       break;
1057     }
1058
1059     // At this point, Offset points to the next field after Length.
1060     // Length is the structure size excluding itself. Compute an offset one
1061     // past the end of the structure (needed to know how many instructions to
1062     // read).
1063     uint64_t StartStructureOffset = Offset;
1064     uint64_t EndStructureOffset = Offset + Length;
1065
1066     // The Id field's size depends on the DWARF format
1067     Error Err = Error::success();
1068     uint64_t Id = Data.getRelocatedValue((IsDWARF64 && !IsEH) ? 8 : 4, &Offset,
1069                                          /*SectionIndex=*/nullptr, &Err);
1070     if (Err)
1071       return Err;
1072
1073     if (Id == getCIEId(IsDWARF64, IsEH)) {
1074       uint8_t Version = Data.getU8(&Offset);
1075       const char *Augmentation = Data.getCStr(&Offset);
1076       StringRef AugmentationString(Augmentation ? Augmentation : "");
1077       uint8_t AddressSize = Version < 4 ? Data.getAddressSize() :
1078                                           Data.getU8(&Offset);
1079       Data.setAddressSize(AddressSize);
1080       uint8_t SegmentDescriptorSize = Version < 4 ? 0 : Data.getU8(&Offset);
1081       uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset);
1082       int64_t DataAlignmentFactor = Data.getSLEB128(&Offset);
1083       uint64_t ReturnAddressRegister =
1084           Version == 1 ? Data.getU8(&Offset) : Data.getULEB128(&Offset);
1085
1086       // Parse the augmentation data for EH CIEs
1087       StringRef AugmentationData("");
1088       uint32_t FDEPointerEncoding = DW_EH_PE_absptr;
1089       uint32_t LSDAPointerEncoding = DW_EH_PE_omit;
1090       Optional<uint64_t> Personality;
1091       Optional<uint32_t> PersonalityEncoding;
1092       if (IsEH) {
1093         Optional<uint64_t> AugmentationLength;
1094         uint64_t StartAugmentationOffset;
1095         uint64_t EndAugmentationOffset;
1096
1097         // Walk the augmentation string to get all the augmentation data.
1098         for (unsigned i = 0, e = AugmentationString.size(); i != e; ++i) {
1099           switch (AugmentationString[i]) {
1100           default:
1101             return createStringError(
1102                 errc::invalid_argument,
1103                 "unknown augmentation character in entry at 0x%" PRIx64,
1104                 StartOffset);
1105           case 'L':
1106             LSDAPointerEncoding = Data.getU8(&Offset);
1107             break;
1108           case 'P': {
1109             if (Personality)
1110               return createStringError(
1111                   errc::invalid_argument,
1112                   "duplicate personality in entry at 0x%" PRIx64, StartOffset);
1113             PersonalityEncoding = Data.getU8(&Offset);
1114             Personality = Data.getEncodedPointer(
1115                 &Offset, *PersonalityEncoding,
1116                 EHFrameAddress ? EHFrameAddress + Offset : 0);
1117             break;
1118           }
1119           case 'R':
1120             FDEPointerEncoding = Data.getU8(&Offset);
1121             break;
1122           case 'S':
1123             // Current frame is a signal trampoline.
1124             break;
1125           case 'z':
1126             if (i)
1127               return createStringError(
1128                   errc::invalid_argument,
1129                   "'z' must be the first character at 0x%" PRIx64, StartOffset);
1130             // Parse the augmentation length first.  We only parse it if
1131             // the string contains a 'z'.
1132             AugmentationLength = Data.getULEB128(&Offset);
1133             StartAugmentationOffset = Offset;
1134             EndAugmentationOffset = Offset + *AugmentationLength;
1135             break;
1136           case 'B':
1137             // B-Key is used for signing functions associated with this
1138             // augmentation string
1139             break;
1140           }
1141         }
1142
1143         if (AugmentationLength.hasValue()) {
1144           if (Offset != EndAugmentationOffset)
1145             return createStringError(errc::invalid_argument,
1146                                      "parsing augmentation data at 0x%" PRIx64
1147                                      " failed",
1148                                      StartOffset);
1149           AugmentationData = Data.getData().slice(StartAugmentationOffset,
1150                                                   EndAugmentationOffset);
1151         }
1152       }
1153
1154       auto Cie = std::make_unique<CIE>(
1155           IsDWARF64, StartOffset, Length, Version, AugmentationString,
1156           AddressSize, SegmentDescriptorSize, CodeAlignmentFactor,
1157           DataAlignmentFactor, ReturnAddressRegister, AugmentationData,
1158           FDEPointerEncoding, LSDAPointerEncoding, Personality,
1159           PersonalityEncoding, Arch);
1160       CIEs[StartOffset] = Cie.get();
1161       Entries.emplace_back(std::move(Cie));
1162     } else {
1163       // FDE
1164       uint64_t CIEPointer = Id;
1165       uint64_t InitialLocation = 0;
1166       uint64_t AddressRange = 0;
1167       Optional<uint64_t> LSDAAddress;
1168       CIE *Cie = CIEs[IsEH ? (StartStructureOffset - CIEPointer) : CIEPointer];
1169
1170       if (IsEH) {
1171         // The address size is encoded in the CIE we reference.
1172         if (!Cie)
1173           return createStringError(errc::invalid_argument,
1174                                    "parsing FDE data at 0x%" PRIx64
1175                                    " failed due to missing CIE",
1176                                    StartOffset);
1177         if (auto Val =
1178                 Data.getEncodedPointer(&Offset, Cie->getFDEPointerEncoding(),
1179                                        EHFrameAddress + Offset)) {
1180           InitialLocation = *Val;
1181         }
1182         if (auto Val = Data.getEncodedPointer(
1183                 &Offset, Cie->getFDEPointerEncoding(), 0)) {
1184           AddressRange = *Val;
1185         }
1186
1187         StringRef AugmentationString = Cie->getAugmentationString();
1188         if (!AugmentationString.empty()) {
1189           // Parse the augmentation length and data for this FDE.
1190           uint64_t AugmentationLength = Data.getULEB128(&Offset);
1191
1192           uint64_t EndAugmentationOffset = Offset + AugmentationLength;
1193
1194           // Decode the LSDA if the CIE augmentation string said we should.
1195           if (Cie->getLSDAPointerEncoding() != DW_EH_PE_omit) {
1196             LSDAAddress = Data.getEncodedPointer(
1197                 &Offset, Cie->getLSDAPointerEncoding(),
1198                 EHFrameAddress ? Offset + EHFrameAddress : 0);
1199           }
1200
1201           if (Offset != EndAugmentationOffset)
1202             return createStringError(errc::invalid_argument,
1203                                      "parsing augmentation data at 0x%" PRIx64
1204                                      " failed",
1205                                      StartOffset);
1206         }
1207       } else {
1208         InitialLocation = Data.getRelocatedAddress(&Offset);
1209         AddressRange = Data.getRelocatedAddress(&Offset);
1210       }
1211
1212       Entries.emplace_back(new FDE(IsDWARF64, StartOffset, Length, CIEPointer,
1213                                    InitialLocation, AddressRange, Cie,
1214                                    LSDAAddress, Arch));
1215     }
1216
1217     if (Error E =
1218             Entries.back()->cfis().parse(Data, &Offset, EndStructureOffset))
1219       return E;
1220
1221     if (Offset != EndStructureOffset)
1222       return createStringError(
1223           errc::invalid_argument,
1224           "parsing entry instructions at 0x%" PRIx64 " failed", StartOffset);
1225   }
1226
1227   return Error::success();
1228 }
1229
1230 FrameEntry *DWARFDebugFrame::getEntryAtOffset(uint64_t Offset) const {
1231   auto It = partition_point(Entries, [=](const std::unique_ptr<FrameEntry> &E) {
1232     return E->getOffset() < Offset;
1233   });
1234   if (It != Entries.end() && (*It)->getOffset() == Offset)
1235     return It->get();
1236   return nullptr;
1237 }
1238
1239 void DWARFDebugFrame::dump(raw_ostream &OS, DIDumpOptions DumpOpts,
1240                            const MCRegisterInfo *MRI,
1241                            Optional<uint64_t> Offset) const {
1242   if (Offset) {
1243     if (auto *Entry = getEntryAtOffset(*Offset))
1244       Entry->dump(OS, DumpOpts, MRI, IsEH);
1245     return;
1246   }
1247
1248   OS << "\n";
1249   for (const auto &Entry : Entries)
1250     Entry->dump(OS, DumpOpts, MRI, IsEH);
1251 }