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/Support/Casting.h" 16 #include "llvm/Support/Compiler.h" 17 #include "llvm/Support/DataExtractor.h" 18 #include "llvm/Support/Errc.h" 19 #include "llvm/Support/ErrorHandling.h" 20 #include "llvm/Support/Format.h" 21 #include "llvm/Support/raw_ostream.h" 22 #include <algorithm> 23 #include <cassert> 24 #include <cinttypes> 25 #include <cstdint> 26 #include <string> 27 #include <vector> 28 29 using namespace llvm; 30 using namespace dwarf; 31 32 33 // See DWARF standard v3, section 7.23 34 const uint8_t DWARF_CFI_PRIMARY_OPCODE_MASK = 0xc0; 35 const uint8_t DWARF_CFI_PRIMARY_OPERAND_MASK = 0x3f; 36 37 Error CFIProgram::parse(DWARFDataExtractor Data, uint64_t *Offset, 38 uint64_t EndOffset) { 39 while (*Offset < EndOffset) { 40 uint8_t Opcode = Data.getRelocatedValue(1, Offset); 41 // Some instructions have a primary opcode encoded in the top bits. 42 uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK; 43 44 if (Primary) { 45 // If it's a primary opcode, the first operand is encoded in the bottom 46 // bits of the opcode itself. 47 uint64_t Op1 = Opcode & DWARF_CFI_PRIMARY_OPERAND_MASK; 48 switch (Primary) { 49 default: 50 return createStringError(errc::illegal_byte_sequence, 51 "Invalid primary CFI opcode 0x%" PRIx8, 52 Primary); 53 case DW_CFA_advance_loc: 54 case DW_CFA_restore: 55 addInstruction(Primary, Op1); 56 break; 57 case DW_CFA_offset: 58 addInstruction(Primary, Op1, Data.getULEB128(Offset)); 59 break; 60 } 61 } else { 62 // Extended opcode - its value is Opcode itself. 63 switch (Opcode) { 64 default: 65 return createStringError(errc::illegal_byte_sequence, 66 "Invalid extended CFI opcode 0x%" PRIx8, 67 Opcode); 68 case DW_CFA_nop: 69 case DW_CFA_remember_state: 70 case DW_CFA_restore_state: 71 case DW_CFA_GNU_window_save: 72 // No operands 73 addInstruction(Opcode); 74 break; 75 case DW_CFA_set_loc: 76 // Operands: Address 77 addInstruction(Opcode, Data.getRelocatedAddress(Offset)); 78 break; 79 case DW_CFA_advance_loc1: 80 // Operands: 1-byte delta 81 addInstruction(Opcode, Data.getRelocatedValue(1, Offset)); 82 break; 83 case DW_CFA_advance_loc2: 84 // Operands: 2-byte delta 85 addInstruction(Opcode, Data.getRelocatedValue(2, Offset)); 86 break; 87 case DW_CFA_advance_loc4: 88 // Operands: 4-byte delta 89 addInstruction(Opcode, Data.getRelocatedValue(4, Offset)); 90 break; 91 case DW_CFA_restore_extended: 92 case DW_CFA_undefined: 93 case DW_CFA_same_value: 94 case DW_CFA_def_cfa_register: 95 case DW_CFA_def_cfa_offset: 96 case DW_CFA_GNU_args_size: 97 // Operands: ULEB128 98 addInstruction(Opcode, Data.getULEB128(Offset)); 99 break; 100 case DW_CFA_def_cfa_offset_sf: 101 // Operands: SLEB128 102 addInstruction(Opcode, Data.getSLEB128(Offset)); 103 break; 104 case DW_CFA_offset_extended: 105 case DW_CFA_register: 106 case DW_CFA_def_cfa: 107 case DW_CFA_val_offset: { 108 // Operands: ULEB128, ULEB128 109 // Note: We can not embed getULEB128 directly into function 110 // argument list. getULEB128 changes Offset and order of evaluation 111 // for arguments is unspecified. 112 auto op1 = Data.getULEB128(Offset); 113 auto op2 = Data.getULEB128(Offset); 114 addInstruction(Opcode, op1, op2); 115 break; 116 } 117 case DW_CFA_offset_extended_sf: 118 case DW_CFA_def_cfa_sf: 119 case DW_CFA_val_offset_sf: { 120 // Operands: ULEB128, SLEB128 121 // Note: see comment for the previous case 122 auto op1 = Data.getULEB128(Offset); 123 auto op2 = (uint64_t)Data.getSLEB128(Offset); 124 addInstruction(Opcode, op1, op2); 125 break; 126 } 127 case DW_CFA_def_cfa_expression: { 128 uint32_t ExprLength = Data.getULEB128(Offset); 129 addInstruction(Opcode, 0); 130 DataExtractor Extractor( 131 Data.getData().slice(*Offset, *Offset + ExprLength), 132 Data.isLittleEndian(), Data.getAddressSize()); 133 // Note. We do not pass the DWARF format to DWARFExpression, because 134 // DW_OP_call_ref, the only operation which depends on the format, is 135 // prohibited in call frame instructions, see sec. 6.4.2 in DWARFv5. 136 Instructions.back().Expression = 137 DWARFExpression(Extractor, Data.getAddressSize()); 138 *Offset += ExprLength; 139 break; 140 } 141 case DW_CFA_expression: 142 case DW_CFA_val_expression: { 143 auto RegNum = Data.getULEB128(Offset); 144 auto BlockLength = Data.getULEB128(Offset); 145 addInstruction(Opcode, RegNum, 0); 146 DataExtractor Extractor( 147 Data.getData().slice(*Offset, *Offset + BlockLength), 148 Data.isLittleEndian(), Data.getAddressSize()); 149 // Note. We do not pass the DWARF format to DWARFExpression, because 150 // DW_OP_call_ref, the only operation which depends on the format, is 151 // prohibited in call frame instructions, see sec. 6.4.2 in DWARFv5. 152 Instructions.back().Expression = 153 DWARFExpression(Extractor, Data.getAddressSize()); 154 *Offset += BlockLength; 155 break; 156 } 157 } 158 } 159 } 160 161 return Error::success(); 162 } 163 164 namespace { 165 166 167 } // end anonymous namespace 168 169 ArrayRef<CFIProgram::OperandType[2]> CFIProgram::getOperandTypes() { 170 static OperandType OpTypes[DW_CFA_restore+1][2]; 171 static bool Initialized = false; 172 if (Initialized) { 173 return ArrayRef<OperandType[2]>(&OpTypes[0], DW_CFA_restore+1); 174 } 175 Initialized = true; 176 177 #define DECLARE_OP2(OP, OPTYPE0, OPTYPE1) \ 178 do { \ 179 OpTypes[OP][0] = OPTYPE0; \ 180 OpTypes[OP][1] = OPTYPE1; \ 181 } while (false) 182 #define DECLARE_OP1(OP, OPTYPE0) DECLARE_OP2(OP, OPTYPE0, OT_None) 183 #define DECLARE_OP0(OP) DECLARE_OP1(OP, OT_None) 184 185 DECLARE_OP1(DW_CFA_set_loc, OT_Address); 186 DECLARE_OP1(DW_CFA_advance_loc, OT_FactoredCodeOffset); 187 DECLARE_OP1(DW_CFA_advance_loc1, OT_FactoredCodeOffset); 188 DECLARE_OP1(DW_CFA_advance_loc2, OT_FactoredCodeOffset); 189 DECLARE_OP1(DW_CFA_advance_loc4, OT_FactoredCodeOffset); 190 DECLARE_OP1(DW_CFA_MIPS_advance_loc8, OT_FactoredCodeOffset); 191 DECLARE_OP2(DW_CFA_def_cfa, OT_Register, OT_Offset); 192 DECLARE_OP2(DW_CFA_def_cfa_sf, OT_Register, OT_SignedFactDataOffset); 193 DECLARE_OP1(DW_CFA_def_cfa_register, OT_Register); 194 DECLARE_OP1(DW_CFA_def_cfa_offset, OT_Offset); 195 DECLARE_OP1(DW_CFA_def_cfa_offset_sf, OT_SignedFactDataOffset); 196 DECLARE_OP1(DW_CFA_def_cfa_expression, OT_Expression); 197 DECLARE_OP1(DW_CFA_undefined, OT_Register); 198 DECLARE_OP1(DW_CFA_same_value, OT_Register); 199 DECLARE_OP2(DW_CFA_offset, OT_Register, OT_UnsignedFactDataOffset); 200 DECLARE_OP2(DW_CFA_offset_extended, OT_Register, OT_UnsignedFactDataOffset); 201 DECLARE_OP2(DW_CFA_offset_extended_sf, OT_Register, OT_SignedFactDataOffset); 202 DECLARE_OP2(DW_CFA_val_offset, OT_Register, OT_UnsignedFactDataOffset); 203 DECLARE_OP2(DW_CFA_val_offset_sf, OT_Register, OT_SignedFactDataOffset); 204 DECLARE_OP2(DW_CFA_register, OT_Register, OT_Register); 205 DECLARE_OP2(DW_CFA_expression, OT_Register, OT_Expression); 206 DECLARE_OP2(DW_CFA_val_expression, OT_Register, OT_Expression); 207 DECLARE_OP1(DW_CFA_restore, OT_Register); 208 DECLARE_OP1(DW_CFA_restore_extended, OT_Register); 209 DECLARE_OP0(DW_CFA_remember_state); 210 DECLARE_OP0(DW_CFA_restore_state); 211 DECLARE_OP0(DW_CFA_GNU_window_save); 212 DECLARE_OP1(DW_CFA_GNU_args_size, OT_Offset); 213 DECLARE_OP0(DW_CFA_nop); 214 215 #undef DECLARE_OP0 216 #undef DECLARE_OP1 217 #undef DECLARE_OP2 218 219 return ArrayRef<OperandType[2]>(&OpTypes[0], DW_CFA_restore+1); 220 } 221 222 /// Print \p Opcode's operand number \p OperandIdx which has value \p Operand. 223 void CFIProgram::printOperand(raw_ostream &OS, const MCRegisterInfo *MRI, 224 bool IsEH, const Instruction &Instr, 225 unsigned OperandIdx, uint64_t Operand) const { 226 assert(OperandIdx < 2); 227 uint8_t Opcode = Instr.Opcode; 228 OperandType Type = getOperandTypes()[Opcode][OperandIdx]; 229 230 switch (Type) { 231 case OT_Unset: { 232 OS << " Unsupported " << (OperandIdx ? "second" : "first") << " operand to"; 233 auto OpcodeName = CallFrameString(Opcode, Arch); 234 if (!OpcodeName.empty()) 235 OS << " " << OpcodeName; 236 else 237 OS << format(" Opcode %x", Opcode); 238 break; 239 } 240 case OT_None: 241 break; 242 case OT_Address: 243 OS << format(" %" PRIx64, Operand); 244 break; 245 case OT_Offset: 246 // The offsets are all encoded in a unsigned form, but in practice 247 // consumers use them signed. It's most certainly legacy due to 248 // the lack of signed variants in the first Dwarf standards. 249 OS << format(" %+" PRId64, int64_t(Operand)); 250 break; 251 case OT_FactoredCodeOffset: // Always Unsigned 252 if (CodeAlignmentFactor) 253 OS << format(" %" PRId64, Operand * CodeAlignmentFactor); 254 else 255 OS << format(" %" PRId64 "*code_alignment_factor" , Operand); 256 break; 257 case OT_SignedFactDataOffset: 258 if (DataAlignmentFactor) 259 OS << format(" %" PRId64, int64_t(Operand) * DataAlignmentFactor); 260 else 261 OS << format(" %" PRId64 "*data_alignment_factor" , int64_t(Operand)); 262 break; 263 case OT_UnsignedFactDataOffset: 264 if (DataAlignmentFactor) 265 OS << format(" %" PRId64, Operand * DataAlignmentFactor); 266 else 267 OS << format(" %" PRId64 "*data_alignment_factor" , Operand); 268 break; 269 case OT_Register: 270 OS << format(" reg%" PRId64, Operand); 271 break; 272 case OT_Expression: 273 assert(Instr.Expression && "missing DWARFExpression object"); 274 OS << " "; 275 Instr.Expression->print(OS, MRI, nullptr, IsEH); 276 break; 277 } 278 } 279 280 void CFIProgram::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH, 281 unsigned IndentLevel) const { 282 for (const auto &Instr : Instructions) { 283 uint8_t Opcode = Instr.Opcode; 284 if (Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK) 285 Opcode &= DWARF_CFI_PRIMARY_OPCODE_MASK; 286 OS.indent(2 * IndentLevel); 287 OS << CallFrameString(Opcode, Arch) << ":"; 288 for (unsigned i = 0; i < Instr.Ops.size(); ++i) 289 printOperand(OS, MRI, IsEH, Instr, i, Instr.Ops[i]); 290 OS << '\n'; 291 } 292 } 293 294 // Returns the CIE identifier to be used by the requested format. 295 // CIE ids for .debug_frame sections are defined in Section 7.24 of DWARFv5. 296 // For CIE ID in .eh_frame sections see 297 // https://refspecs.linuxfoundation.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html 298 constexpr uint64_t getCIEId(bool IsDWARF64, bool IsEH) { 299 if (IsEH) 300 return 0; 301 if (IsDWARF64) 302 return DW64_CIE_ID; 303 return DW_CIE_ID; 304 } 305 306 void CIE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const { 307 OS << format("%08" PRIx64, Offset) 308 << format(" %0*" PRIx64, IsDWARF64 ? 16 : 8, Length) 309 << format(" %0*" PRIx64, IsDWARF64 && !IsEH ? 16 : 8, 310 getCIEId(IsDWARF64, IsEH)) 311 << " CIE\n"; 312 OS << format(" Version: %d\n", Version); 313 OS << " Augmentation: \"" << Augmentation << "\"\n"; 314 if (Version >= 4) { 315 OS << format(" Address size: %u\n", (uint32_t)AddressSize); 316 OS << format(" Segment desc size: %u\n", 317 (uint32_t)SegmentDescriptorSize); 318 } 319 OS << format(" Code alignment factor: %u\n", (uint32_t)CodeAlignmentFactor); 320 OS << format(" Data alignment factor: %d\n", (int32_t)DataAlignmentFactor); 321 OS << format(" Return address column: %d\n", (int32_t)ReturnAddressRegister); 322 if (Personality) 323 OS << format(" Personality Address: %016" PRIx64 "\n", *Personality); 324 if (!AugmentationData.empty()) { 325 OS << " Augmentation data: "; 326 for (uint8_t Byte : AugmentationData) 327 OS << ' ' << hexdigit(Byte >> 4) << hexdigit(Byte & 0xf); 328 OS << "\n"; 329 } 330 OS << "\n"; 331 CFIs.dump(OS, MRI, IsEH); 332 OS << "\n"; 333 } 334 335 void FDE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const { 336 OS << format("%08" PRIx64, Offset) 337 << format(" %0*" PRIx64, IsDWARF64 ? 16 : 8, Length) 338 << format(" %0*" PRIx64, IsDWARF64 && !IsEH ? 16 : 8, CIEPointer) 339 << " FDE cie="; 340 if (LinkedCIE) 341 OS << format("%08" PRIx64, LinkedCIE->getOffset()); 342 else 343 OS << "<invalid offset>"; 344 OS << format(" pc=%08" PRIx64 "...%08" PRIx64 "\n", InitialLocation, 345 InitialLocation + AddressRange); 346 if (LSDAAddress) 347 OS << format(" LSDA Address: %016" PRIx64 "\n", *LSDAAddress); 348 CFIs.dump(OS, MRI, IsEH); 349 OS << "\n"; 350 } 351 352 DWARFDebugFrame::DWARFDebugFrame(Triple::ArchType Arch, 353 bool IsEH, uint64_t EHFrameAddress) 354 : Arch(Arch), IsEH(IsEH), EHFrameAddress(EHFrameAddress) {} 355 356 DWARFDebugFrame::~DWARFDebugFrame() = default; 357 358 static void LLVM_ATTRIBUTE_UNUSED dumpDataAux(DataExtractor Data, 359 uint64_t Offset, int Length) { 360 errs() << "DUMP: "; 361 for (int i = 0; i < Length; ++i) { 362 uint8_t c = Data.getU8(&Offset); 363 errs().write_hex(c); errs() << " "; 364 } 365 errs() << "\n"; 366 } 367 368 Error DWARFDebugFrame::parse(DWARFDataExtractor Data) { 369 uint64_t Offset = 0; 370 DenseMap<uint64_t, CIE *> CIEs; 371 372 while (Data.isValidOffset(Offset)) { 373 uint64_t StartOffset = Offset; 374 375 uint64_t Length; 376 DwarfFormat Format; 377 std::tie(Length, Format) = Data.getInitialLength(&Offset); 378 uint64_t Id; 379 380 // At this point, Offset points to the next field after Length. 381 // Length is the structure size excluding itself. Compute an offset one 382 // past the end of the structure (needed to know how many instructions to 383 // read). 384 uint64_t StartStructureOffset = Offset; 385 uint64_t EndStructureOffset = Offset + Length; 386 387 // The Id field's size depends on the DWARF format 388 bool IsDWARF64 = Format == DWARF64; 389 Id = Data.getRelocatedValue((IsDWARF64 && !IsEH) ? 8 : 4, &Offset); 390 if (Id == getCIEId(IsDWARF64, IsEH)) { 391 uint8_t Version = Data.getU8(&Offset); 392 const char *Augmentation = Data.getCStr(&Offset); 393 StringRef AugmentationString(Augmentation ? Augmentation : ""); 394 uint8_t AddressSize = Version < 4 ? Data.getAddressSize() : 395 Data.getU8(&Offset); 396 Data.setAddressSize(AddressSize); 397 uint8_t SegmentDescriptorSize = Version < 4 ? 0 : Data.getU8(&Offset); 398 uint64_t CodeAlignmentFactor = Data.getULEB128(&Offset); 399 int64_t DataAlignmentFactor = Data.getSLEB128(&Offset); 400 uint64_t ReturnAddressRegister = 401 Version == 1 ? Data.getU8(&Offset) : Data.getULEB128(&Offset); 402 403 // Parse the augmentation data for EH CIEs 404 StringRef AugmentationData(""); 405 uint32_t FDEPointerEncoding = DW_EH_PE_absptr; 406 uint32_t LSDAPointerEncoding = DW_EH_PE_omit; 407 Optional<uint64_t> Personality; 408 Optional<uint32_t> PersonalityEncoding; 409 if (IsEH) { 410 Optional<uint64_t> AugmentationLength; 411 uint64_t StartAugmentationOffset; 412 uint64_t EndAugmentationOffset; 413 414 // Walk the augmentation string to get all the augmentation data. 415 for (unsigned i = 0, e = AugmentationString.size(); i != e; ++i) { 416 switch (AugmentationString[i]) { 417 default: 418 return createStringError( 419 errc::invalid_argument, 420 "unknown augmentation character in entry at 0x%" PRIx64, 421 StartOffset); 422 case 'L': 423 LSDAPointerEncoding = Data.getU8(&Offset); 424 break; 425 case 'P': { 426 if (Personality) 427 return createStringError( 428 errc::invalid_argument, 429 "duplicate personality in entry at 0x%" PRIx64, StartOffset); 430 PersonalityEncoding = Data.getU8(&Offset); 431 Personality = Data.getEncodedPointer( 432 &Offset, *PersonalityEncoding, 433 EHFrameAddress ? EHFrameAddress + Offset : 0); 434 break; 435 } 436 case 'R': 437 FDEPointerEncoding = Data.getU8(&Offset); 438 break; 439 case 'S': 440 // Current frame is a signal trampoline. 441 break; 442 case 'z': 443 if (i) 444 return createStringError( 445 errc::invalid_argument, 446 "'z' must be the first character at 0x%" PRIx64, StartOffset); 447 // Parse the augmentation length first. We only parse it if 448 // the string contains a 'z'. 449 AugmentationLength = Data.getULEB128(&Offset); 450 StartAugmentationOffset = Offset; 451 EndAugmentationOffset = Offset + *AugmentationLength; 452 break; 453 case 'B': 454 // B-Key is used for signing functions associated with this 455 // augmentation string 456 break; 457 } 458 } 459 460 if (AugmentationLength.hasValue()) { 461 if (Offset != EndAugmentationOffset) 462 return createStringError(errc::invalid_argument, 463 "parsing augmentation data at 0x%" PRIx64 464 " failed", 465 StartOffset); 466 AugmentationData = Data.getData().slice(StartAugmentationOffset, 467 EndAugmentationOffset); 468 } 469 } 470 471 auto Cie = std::make_unique<CIE>( 472 IsDWARF64, StartOffset, Length, Version, AugmentationString, 473 AddressSize, SegmentDescriptorSize, CodeAlignmentFactor, 474 DataAlignmentFactor, ReturnAddressRegister, AugmentationData, 475 FDEPointerEncoding, LSDAPointerEncoding, Personality, 476 PersonalityEncoding, Arch); 477 CIEs[StartOffset] = Cie.get(); 478 Entries.emplace_back(std::move(Cie)); 479 } else { 480 // FDE 481 uint64_t CIEPointer = Id; 482 uint64_t InitialLocation = 0; 483 uint64_t AddressRange = 0; 484 Optional<uint64_t> LSDAAddress; 485 CIE *Cie = CIEs[IsEH ? (StartStructureOffset - CIEPointer) : CIEPointer]; 486 487 if (IsEH) { 488 // The address size is encoded in the CIE we reference. 489 if (!Cie) 490 return createStringError(errc::invalid_argument, 491 "parsing FDE data at 0x%" PRIx64 492 " failed due to missing CIE", 493 StartOffset); 494 if (auto Val = Data.getEncodedPointer( 495 &Offset, Cie->getFDEPointerEncoding(), 496 EHFrameAddress ? EHFrameAddress + Offset : 0)) { 497 InitialLocation = *Val; 498 } 499 if (auto Val = Data.getEncodedPointer( 500 &Offset, Cie->getFDEPointerEncoding(), 0)) { 501 AddressRange = *Val; 502 } 503 504 StringRef AugmentationString = Cie->getAugmentationString(); 505 if (!AugmentationString.empty()) { 506 // Parse the augmentation length and data for this FDE. 507 uint64_t AugmentationLength = Data.getULEB128(&Offset); 508 509 uint64_t EndAugmentationOffset = Offset + AugmentationLength; 510 511 // Decode the LSDA if the CIE augmentation string said we should. 512 if (Cie->getLSDAPointerEncoding() != DW_EH_PE_omit) { 513 LSDAAddress = Data.getEncodedPointer( 514 &Offset, Cie->getLSDAPointerEncoding(), 515 EHFrameAddress ? Offset + EHFrameAddress : 0); 516 } 517 518 if (Offset != EndAugmentationOffset) 519 return createStringError(errc::invalid_argument, 520 "parsing augmentation data at 0x%" PRIx64 521 " failed", 522 StartOffset); 523 } 524 } else { 525 InitialLocation = Data.getRelocatedAddress(&Offset); 526 AddressRange = Data.getRelocatedAddress(&Offset); 527 } 528 529 Entries.emplace_back(new FDE(IsDWARF64, StartOffset, Length, CIEPointer, 530 InitialLocation, AddressRange, Cie, 531 LSDAAddress, Arch)); 532 } 533 534 if (Error E = 535 Entries.back()->cfis().parse(Data, &Offset, EndStructureOffset)) 536 return E; 537 538 if (Offset != EndStructureOffset) 539 return createStringError( 540 errc::invalid_argument, 541 "parsing entry instructions at 0x%" PRIx64 " failed", StartOffset); 542 } 543 544 return Error::success(); 545 } 546 547 FrameEntry *DWARFDebugFrame::getEntryAtOffset(uint64_t Offset) const { 548 auto It = partition_point(Entries, [=](const std::unique_ptr<FrameEntry> &E) { 549 return E->getOffset() < Offset; 550 }); 551 if (It != Entries.end() && (*It)->getOffset() == Offset) 552 return It->get(); 553 return nullptr; 554 } 555 556 void DWARFDebugFrame::dump(raw_ostream &OS, const MCRegisterInfo *MRI, 557 Optional<uint64_t> Offset) const { 558 if (Offset) { 559 if (auto *Entry = getEntryAtOffset(*Offset)) 560 Entry->dump(OS, MRI, IsEH); 561 return; 562 } 563 564 OS << "\n"; 565 for (const auto &Entry : Entries) 566 Entry->dump(OS, MRI, IsEH); 567 } 568