1 //===- DWARFDebugFrame.h - Parsing of .debug_frame ------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 #include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
11 #include "llvm/ADT/DenseMap.h"
12 #include "llvm/ADT/Optional.h"
13 #include "llvm/ADT/StringExtras.h"
14 #include "llvm/ADT/StringRef.h"
15 #include "llvm/BinaryFormat/Dwarf.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 #include <string>
28 #include <vector>
29
30 using namespace llvm;
31 using namespace dwarf;
32
33
34 // See DWARF standard v3, section 7.23
35 const uint8_t DWARF_CFI_PRIMARY_OPCODE_MASK = 0xc0;
36 const uint8_t DWARF_CFI_PRIMARY_OPERAND_MASK = 0x3f;
37
parse(DataExtractor Data,uint32_t * Offset,uint32_t EndOffset)38 Error CFIProgram::parse(DataExtractor Data, uint32_t *Offset,
39 uint32_t EndOffset) {
40 while (*Offset < EndOffset) {
41 uint8_t Opcode = Data.getU8(Offset);
42 // Some instructions have a primary opcode encoded in the top bits.
43 uint8_t Primary = Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK;
44
45 if (Primary) {
46 // If it's a primary opcode, the first operand is encoded in the bottom
47 // bits of the opcode itself.
48 uint64_t Op1 = Opcode & DWARF_CFI_PRIMARY_OPERAND_MASK;
49 switch (Primary) {
50 default:
51 return createStringError(errc::illegal_byte_sequence,
52 "Invalid primary CFI opcode 0x%" PRIx8,
53 Primary);
54 case DW_CFA_advance_loc:
55 case DW_CFA_restore:
56 addInstruction(Primary, Op1);
57 break;
58 case DW_CFA_offset:
59 addInstruction(Primary, Op1, Data.getULEB128(Offset));
60 break;
61 }
62 } else {
63 // Extended opcode - its value is Opcode itself.
64 switch (Opcode) {
65 default:
66 return createStringError(errc::illegal_byte_sequence,
67 "Invalid extended CFI opcode 0x%" PRIx8,
68 Opcode);
69 case DW_CFA_nop:
70 case DW_CFA_remember_state:
71 case DW_CFA_restore_state:
72 case DW_CFA_GNU_window_save:
73 // No operands
74 addInstruction(Opcode);
75 break;
76 case DW_CFA_set_loc:
77 // Operands: Address
78 addInstruction(Opcode, Data.getAddress(Offset));
79 break;
80 case DW_CFA_advance_loc1:
81 // Operands: 1-byte delta
82 addInstruction(Opcode, Data.getU8(Offset));
83 break;
84 case DW_CFA_advance_loc2:
85 // Operands: 2-byte delta
86 addInstruction(Opcode, Data.getU16(Offset));
87 break;
88 case DW_CFA_advance_loc4:
89 // Operands: 4-byte delta
90 addInstruction(Opcode, Data.getU32(Offset));
91 break;
92 case DW_CFA_restore_extended:
93 case DW_CFA_undefined:
94 case DW_CFA_same_value:
95 case DW_CFA_def_cfa_register:
96 case DW_CFA_def_cfa_offset:
97 case DW_CFA_GNU_args_size:
98 // Operands: ULEB128
99 addInstruction(Opcode, Data.getULEB128(Offset));
100 break;
101 case DW_CFA_def_cfa_offset_sf:
102 // Operands: SLEB128
103 addInstruction(Opcode, Data.getSLEB128(Offset));
104 break;
105 case DW_CFA_offset_extended:
106 case DW_CFA_register:
107 case DW_CFA_def_cfa:
108 case DW_CFA_val_offset: {
109 // Operands: ULEB128, ULEB128
110 // Note: We can not embed getULEB128 directly into function
111 // argument list. getULEB128 changes Offset and order of evaluation
112 // for arguments is unspecified.
113 auto op1 = Data.getULEB128(Offset);
114 auto op2 = Data.getULEB128(Offset);
115 addInstruction(Opcode, op1, op2);
116 break;
117 }
118 case DW_CFA_offset_extended_sf:
119 case DW_CFA_def_cfa_sf:
120 case DW_CFA_val_offset_sf: {
121 // Operands: ULEB128, SLEB128
122 // Note: see comment for the previous case
123 auto op1 = Data.getULEB128(Offset);
124 auto op2 = (uint64_t)Data.getSLEB128(Offset);
125 addInstruction(Opcode, op1, op2);
126 break;
127 }
128 case DW_CFA_def_cfa_expression: {
129 uint32_t ExprLength = Data.getULEB128(Offset);
130 addInstruction(Opcode, 0);
131 DataExtractor Extractor(
132 Data.getData().slice(*Offset, *Offset + ExprLength),
133 Data.isLittleEndian(), Data.getAddressSize());
134 Instructions.back().Expression = DWARFExpression(
135 Extractor, Data.getAddressSize(), dwarf::DWARF_VERSION);
136 *Offset += ExprLength;
137 break;
138 }
139 case DW_CFA_expression:
140 case DW_CFA_val_expression: {
141 auto RegNum = Data.getULEB128(Offset);
142 auto BlockLength = Data.getULEB128(Offset);
143 addInstruction(Opcode, RegNum, 0);
144 DataExtractor Extractor(
145 Data.getData().slice(*Offset, *Offset + BlockLength),
146 Data.isLittleEndian(), Data.getAddressSize());
147 Instructions.back().Expression = DWARFExpression(
148 Extractor, Data.getAddressSize(), dwarf::DWARF_VERSION);
149 *Offset += BlockLength;
150 break;
151 }
152 }
153 }
154 }
155
156 return Error::success();
157 }
158
159 namespace {
160
161
162 } // end anonymous namespace
163
getOperandTypes()164 ArrayRef<CFIProgram::OperandType[2]> CFIProgram::getOperandTypes() {
165 static OperandType OpTypes[DW_CFA_restore+1][2];
166 static bool Initialized = false;
167 if (Initialized) {
168 return ArrayRef<OperandType[2]>(&OpTypes[0], DW_CFA_restore+1);
169 }
170 Initialized = true;
171
172 #define DECLARE_OP2(OP, OPTYPE0, OPTYPE1) \
173 do { \
174 OpTypes[OP][0] = OPTYPE0; \
175 OpTypes[OP][1] = OPTYPE1; \
176 } while (false)
177 #define DECLARE_OP1(OP, OPTYPE0) DECLARE_OP2(OP, OPTYPE0, OT_None)
178 #define DECLARE_OP0(OP) DECLARE_OP1(OP, OT_None)
179
180 DECLARE_OP1(DW_CFA_set_loc, OT_Address);
181 DECLARE_OP1(DW_CFA_advance_loc, OT_FactoredCodeOffset);
182 DECLARE_OP1(DW_CFA_advance_loc1, OT_FactoredCodeOffset);
183 DECLARE_OP1(DW_CFA_advance_loc2, OT_FactoredCodeOffset);
184 DECLARE_OP1(DW_CFA_advance_loc4, OT_FactoredCodeOffset);
185 DECLARE_OP1(DW_CFA_MIPS_advance_loc8, OT_FactoredCodeOffset);
186 DECLARE_OP2(DW_CFA_def_cfa, OT_Register, OT_Offset);
187 DECLARE_OP2(DW_CFA_def_cfa_sf, OT_Register, OT_SignedFactDataOffset);
188 DECLARE_OP1(DW_CFA_def_cfa_register, OT_Register);
189 DECLARE_OP1(DW_CFA_def_cfa_offset, OT_Offset);
190 DECLARE_OP1(DW_CFA_def_cfa_offset_sf, OT_SignedFactDataOffset);
191 DECLARE_OP1(DW_CFA_def_cfa_expression, OT_Expression);
192 DECLARE_OP1(DW_CFA_undefined, OT_Register);
193 DECLARE_OP1(DW_CFA_same_value, OT_Register);
194 DECLARE_OP2(DW_CFA_offset, OT_Register, OT_UnsignedFactDataOffset);
195 DECLARE_OP2(DW_CFA_offset_extended, OT_Register, OT_UnsignedFactDataOffset);
196 DECLARE_OP2(DW_CFA_offset_extended_sf, OT_Register, OT_SignedFactDataOffset);
197 DECLARE_OP2(DW_CFA_val_offset, OT_Register, OT_UnsignedFactDataOffset);
198 DECLARE_OP2(DW_CFA_val_offset_sf, OT_Register, OT_SignedFactDataOffset);
199 DECLARE_OP2(DW_CFA_register, OT_Register, OT_Register);
200 DECLARE_OP2(DW_CFA_expression, OT_Register, OT_Expression);
201 DECLARE_OP2(DW_CFA_val_expression, OT_Register, OT_Expression);
202 DECLARE_OP1(DW_CFA_restore, OT_Register);
203 DECLARE_OP1(DW_CFA_restore_extended, OT_Register);
204 DECLARE_OP0(DW_CFA_remember_state);
205 DECLARE_OP0(DW_CFA_restore_state);
206 DECLARE_OP0(DW_CFA_GNU_window_save);
207 DECLARE_OP1(DW_CFA_GNU_args_size, OT_Offset);
208 DECLARE_OP0(DW_CFA_nop);
209
210 #undef DECLARE_OP0
211 #undef DECLARE_OP1
212 #undef DECLARE_OP2
213
214 return ArrayRef<OperandType[2]>(&OpTypes[0], DW_CFA_restore+1);
215 }
216
217 /// Print \p Opcode's operand number \p OperandIdx which has value \p Operand.
printOperand(raw_ostream & OS,const MCRegisterInfo * MRI,bool IsEH,const Instruction & Instr,unsigned OperandIdx,uint64_t Operand) const218 void CFIProgram::printOperand(raw_ostream &OS, const MCRegisterInfo *MRI,
219 bool IsEH, const Instruction &Instr,
220 unsigned OperandIdx, uint64_t Operand) const {
221 assert(OperandIdx < 2);
222 uint8_t Opcode = Instr.Opcode;
223 OperandType Type = getOperandTypes()[Opcode][OperandIdx];
224
225 switch (Type) {
226 case OT_Unset: {
227 OS << " Unsupported " << (OperandIdx ? "second" : "first") << " operand to";
228 auto OpcodeName = CallFrameString(Opcode, Arch);
229 if (!OpcodeName.empty())
230 OS << " " << OpcodeName;
231 else
232 OS << format(" Opcode %x", Opcode);
233 break;
234 }
235 case OT_None:
236 break;
237 case OT_Address:
238 OS << format(" %" PRIx64, Operand);
239 break;
240 case OT_Offset:
241 // The offsets are all encoded in a unsigned form, but in practice
242 // consumers use them signed. It's most certainly legacy due to
243 // the lack of signed variants in the first Dwarf standards.
244 OS << format(" %+" PRId64, int64_t(Operand));
245 break;
246 case OT_FactoredCodeOffset: // Always Unsigned
247 if (CodeAlignmentFactor)
248 OS << format(" %" PRId64, Operand * CodeAlignmentFactor);
249 else
250 OS << format(" %" PRId64 "*code_alignment_factor" , Operand);
251 break;
252 case OT_SignedFactDataOffset:
253 if (DataAlignmentFactor)
254 OS << format(" %" PRId64, int64_t(Operand) * DataAlignmentFactor);
255 else
256 OS << format(" %" PRId64 "*data_alignment_factor" , int64_t(Operand));
257 break;
258 case OT_UnsignedFactDataOffset:
259 if (DataAlignmentFactor)
260 OS << format(" %" PRId64, Operand * DataAlignmentFactor);
261 else
262 OS << format(" %" PRId64 "*data_alignment_factor" , Operand);
263 break;
264 case OT_Register:
265 OS << format(" reg%" PRId64, Operand);
266 break;
267 case OT_Expression:
268 assert(Instr.Expression && "missing DWARFExpression object");
269 OS << " ";
270 Instr.Expression->print(OS, MRI, IsEH);
271 break;
272 }
273 }
274
dump(raw_ostream & OS,const MCRegisterInfo * MRI,bool IsEH,unsigned IndentLevel) const275 void CFIProgram::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH,
276 unsigned IndentLevel) const {
277 for (const auto &Instr : Instructions) {
278 uint8_t Opcode = Instr.Opcode;
279 if (Opcode & DWARF_CFI_PRIMARY_OPCODE_MASK)
280 Opcode &= DWARF_CFI_PRIMARY_OPCODE_MASK;
281 OS.indent(2 * IndentLevel);
282 OS << CallFrameString(Opcode, Arch) << ":";
283 for (unsigned i = 0; i < Instr.Ops.size(); ++i)
284 printOperand(OS, MRI, IsEH, Instr, i, Instr.Ops[i]);
285 OS << '\n';
286 }
287 }
288
dump(raw_ostream & OS,const MCRegisterInfo * MRI,bool IsEH) const289 void CIE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const {
290 OS << format("%08x %08x %08x CIE", (uint32_t)Offset, (uint32_t)Length,
291 DW_CIE_ID)
292 << "\n";
293 OS << format(" Version: %d\n", Version);
294 OS << " Augmentation: \"" << Augmentation << "\"\n";
295 if (Version >= 4) {
296 OS << format(" Address size: %u\n", (uint32_t)AddressSize);
297 OS << format(" Segment desc size: %u\n",
298 (uint32_t)SegmentDescriptorSize);
299 }
300 OS << format(" Code alignment factor: %u\n", (uint32_t)CodeAlignmentFactor);
301 OS << format(" Data alignment factor: %d\n", (int32_t)DataAlignmentFactor);
302 OS << format(" Return address column: %d\n", (int32_t)ReturnAddressRegister);
303 if (Personality)
304 OS << format(" Personality Address: %016" PRIx64 "\n", *Personality);
305 if (!AugmentationData.empty()) {
306 OS << " Augmentation data: ";
307 for (uint8_t Byte : AugmentationData)
308 OS << ' ' << hexdigit(Byte >> 4) << hexdigit(Byte & 0xf);
309 OS << "\n";
310 }
311 OS << "\n";
312 CFIs.dump(OS, MRI, IsEH);
313 OS << "\n";
314 }
315
dump(raw_ostream & OS,const MCRegisterInfo * MRI,bool IsEH) const316 void FDE::dump(raw_ostream &OS, const MCRegisterInfo *MRI, bool IsEH) const {
317 OS << format("%08x %08x %08x FDE ", (uint32_t)Offset, (uint32_t)Length,
318 (int32_t)LinkedCIEOffset);
319 OS << format("cie=%08x pc=%08x...%08x\n", (int32_t)LinkedCIEOffset,
320 (uint32_t)InitialLocation,
321 (uint32_t)InitialLocation + (uint32_t)AddressRange);
322 if (LSDAAddress)
323 OS << format(" LSDA Address: %016" PRIx64 "\n", *LSDAAddress);
324 CFIs.dump(OS, MRI, IsEH);
325 OS << "\n";
326 }
327
DWARFDebugFrame(Triple::ArchType Arch,bool IsEH,uint64_t EHFrameAddress)328 DWARFDebugFrame::DWARFDebugFrame(Triple::ArchType Arch,
329 bool IsEH, uint64_t EHFrameAddress)
330 : Arch(Arch), IsEH(IsEH), EHFrameAddress(EHFrameAddress) {}
331
332 DWARFDebugFrame::~DWARFDebugFrame() = default;
333
dumpDataAux(DataExtractor Data,uint32_t Offset,int Length)334 static void LLVM_ATTRIBUTE_UNUSED dumpDataAux(DataExtractor Data,
335 uint32_t Offset, int Length) {
336 errs() << "DUMP: ";
337 for (int i = 0; i < Length; ++i) {
338 uint8_t c = Data.getU8(&Offset);
339 errs().write_hex(c); errs() << " ";
340 }
341 errs() << "\n";
342 }
343
344 // This is a workaround for old compilers which do not allow
345 // noreturn attribute usage in lambdas. Once the support for those
346 // compilers are phased out, we can remove this and return back to
347 // a ReportError lambda: [StartOffset](const char *ErrorMsg).
ReportError(uint32_t StartOffset,const char * ErrorMsg)348 static void LLVM_ATTRIBUTE_NORETURN ReportError(uint32_t StartOffset,
349 const char *ErrorMsg) {
350 std::string Str;
351 raw_string_ostream OS(Str);
352 OS << format(ErrorMsg, StartOffset);
353 OS.flush();
354 report_fatal_error(Str);
355 }
356
parse(DWARFDataExtractor Data)357 void DWARFDebugFrame::parse(DWARFDataExtractor Data) {
358 uint32_t Offset = 0;
359 DenseMap<uint32_t, CIE *> CIEs;
360
361 while (Data.isValidOffset(Offset)) {
362 uint32_t StartOffset = Offset;
363
364 bool IsDWARF64 = false;
365 uint64_t Length = Data.getU32(&Offset);
366 uint64_t Id;
367
368 if (Length == UINT32_MAX) {
369 // DWARF-64 is distinguished by the first 32 bits of the initial length
370 // field being 0xffffffff. Then, the next 64 bits are the actual entry
371 // length.
372 IsDWARF64 = true;
373 Length = Data.getU64(&Offset);
374 }
375
376 // At this point, Offset points to the next field after Length.
377 // Length is the structure size excluding itself. Compute an offset one
378 // past the end of the structure (needed to know how many instructions to
379 // read).
380 // TODO: For honest DWARF64 support, DataExtractor will have to treat
381 // offset_ptr as uint64_t*
382 uint32_t StartStructureOffset = Offset;
383 uint32_t EndStructureOffset = Offset + static_cast<uint32_t>(Length);
384
385 // The Id field's size depends on the DWARF format
386 Id = Data.getUnsigned(&Offset, (IsDWARF64 && !IsEH) ? 8 : 4);
387 bool IsCIE =
388 ((IsDWARF64 && Id == DW64_CIE_ID) || Id == DW_CIE_ID || (IsEH && !Id));
389
390 if (IsCIE) {
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 uint32_t StartAugmentationOffset;
412 uint32_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 ReportError(StartOffset,
419 "Unknown augmentation character in entry at %lx");
420 case 'L':
421 LSDAPointerEncoding = Data.getU8(&Offset);
422 break;
423 case 'P': {
424 if (Personality)
425 ReportError(StartOffset,
426 "Duplicate personality in entry at %lx");
427 PersonalityEncoding = Data.getU8(&Offset);
428 Personality = Data.getEncodedPointer(
429 &Offset, *PersonalityEncoding,
430 EHFrameAddress ? EHFrameAddress + Offset : 0);
431 break;
432 }
433 case 'R':
434 FDEPointerEncoding = Data.getU8(&Offset);
435 break;
436 case 'S':
437 // Current frame is a signal trampoline.
438 break;
439 case 'z':
440 if (i)
441 ReportError(StartOffset,
442 "'z' must be the first character at %lx");
443 // Parse the augmentation length first. We only parse it if
444 // the string contains a 'z'.
445 AugmentationLength = Data.getULEB128(&Offset);
446 StartAugmentationOffset = Offset;
447 EndAugmentationOffset = Offset +
448 static_cast<uint32_t>(*AugmentationLength);
449 break;
450 case 'B':
451 // B-Key is used for signing functions associated with this
452 // augmentation string
453 break;
454 }
455 }
456
457 if (AugmentationLength.hasValue()) {
458 if (Offset != EndAugmentationOffset)
459 ReportError(StartOffset, "Parsing augmentation data at %lx failed");
460
461 AugmentationData = Data.getData().slice(StartAugmentationOffset,
462 EndAugmentationOffset);
463 }
464 }
465
466 auto Cie = llvm::make_unique<CIE>(
467 StartOffset, Length, Version, AugmentationString, AddressSize,
468 SegmentDescriptorSize, CodeAlignmentFactor, DataAlignmentFactor,
469 ReturnAddressRegister, AugmentationData, FDEPointerEncoding,
470 LSDAPointerEncoding, Personality, PersonalityEncoding, Arch);
471 CIEs[StartOffset] = Cie.get();
472 Entries.emplace_back(std::move(Cie));
473 } else {
474 // FDE
475 uint64_t CIEPointer = Id;
476 uint64_t InitialLocation = 0;
477 uint64_t AddressRange = 0;
478 Optional<uint64_t> LSDAAddress;
479 CIE *Cie = CIEs[IsEH ? (StartStructureOffset - CIEPointer) : CIEPointer];
480
481 if (IsEH) {
482 // The address size is encoded in the CIE we reference.
483 if (!Cie)
484 ReportError(StartOffset,
485 "Parsing FDE data at %lx failed due to missing CIE");
486
487 if (auto Val = Data.getEncodedPointer(
488 &Offset, Cie->getFDEPointerEncoding(),
489 EHFrameAddress ? EHFrameAddress + Offset : 0)) {
490 InitialLocation = *Val;
491 }
492 if (auto Val = Data.getEncodedPointer(
493 &Offset, Cie->getFDEPointerEncoding(), 0)) {
494 AddressRange = *Val;
495 }
496
497 StringRef AugmentationString = Cie->getAugmentationString();
498 if (!AugmentationString.empty()) {
499 // Parse the augmentation length and data for this FDE.
500 uint64_t AugmentationLength = Data.getULEB128(&Offset);
501
502 uint32_t EndAugmentationOffset =
503 Offset + static_cast<uint32_t>(AugmentationLength);
504
505 // Decode the LSDA if the CIE augmentation string said we should.
506 if (Cie->getLSDAPointerEncoding() != DW_EH_PE_omit) {
507 LSDAAddress = Data.getEncodedPointer(
508 &Offset, Cie->getLSDAPointerEncoding(),
509 EHFrameAddress ? Offset + EHFrameAddress : 0);
510 }
511
512 if (Offset != EndAugmentationOffset)
513 ReportError(StartOffset, "Parsing augmentation data at %lx failed");
514 }
515 } else {
516 InitialLocation = Data.getAddress(&Offset);
517 AddressRange = Data.getAddress(&Offset);
518 }
519
520 Entries.emplace_back(new FDE(StartOffset, Length, CIEPointer,
521 InitialLocation, AddressRange,
522 Cie, LSDAAddress, Arch));
523 }
524
525 if (Error E =
526 Entries.back()->cfis().parse(Data, &Offset, EndStructureOffset)) {
527 report_fatal_error(toString(std::move(E)));
528 }
529
530 if (Offset != EndStructureOffset)
531 ReportError(StartOffset, "Parsing entry instructions at %lx failed");
532 }
533 }
534
getEntryAtOffset(uint64_t Offset) const535 FrameEntry *DWARFDebugFrame::getEntryAtOffset(uint64_t Offset) const {
536 auto It =
537 std::lower_bound(Entries.begin(), Entries.end(), Offset,
538 [](const std::unique_ptr<FrameEntry> &E,
539 uint64_t Offset) { return E->getOffset() < Offset; });
540 if (It != Entries.end() && (*It)->getOffset() == Offset)
541 return It->get();
542 return nullptr;
543 }
544
dump(raw_ostream & OS,const MCRegisterInfo * MRI,Optional<uint64_t> Offset) const545 void DWARFDebugFrame::dump(raw_ostream &OS, const MCRegisterInfo *MRI,
546 Optional<uint64_t> Offset) const {
547 if (Offset) {
548 if (auto *Entry = getEntryAtOffset(*Offset))
549 Entry->dump(OS, MRI, IsEH);
550 return;
551 }
552
553 OS << "\n";
554 for (const auto &Entry : Entries)
555 Entry->dump(OS, MRI, IsEH);
556 }
557