xref: /freebsd/contrib/llvm-project/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp (revision 9dba64be9536c28e4800e06512b7f29b43ade345)
1 //===- DWARFContext.cpp ---------------------------------------------------===//
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/DWARFContext.h"
10 #include "llvm/ADT/STLExtras.h"
11 #include "llvm/ADT/SmallString.h"
12 #include "llvm/ADT/SmallVector.h"
13 #include "llvm/ADT/StringRef.h"
14 #include "llvm/ADT/StringSwitch.h"
15 #include "llvm/BinaryFormat/Dwarf.h"
16 #include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
17 #include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
18 #include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
19 #include "llvm/DebugInfo/DWARF/DWARFDebugAddr.h"
20 #include "llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h"
21 #include "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
22 #include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
23 #include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
24 #include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
25 #include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
26 #include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
27 #include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
28 #include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h"
29 #include "llvm/DebugInfo/DWARF/DWARFDie.h"
30 #include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
31 #include "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
32 #include "llvm/DebugInfo/DWARF/DWARFSection.h"
33 #include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
34 #include "llvm/DebugInfo/DWARF/DWARFVerifier.h"
35 #include "llvm/MC/MCRegisterInfo.h"
36 #include "llvm/Object/Decompressor.h"
37 #include "llvm/Object/MachO.h"
38 #include "llvm/Object/ObjectFile.h"
39 #include "llvm/Object/RelocationResolver.h"
40 #include "llvm/Support/Casting.h"
41 #include "llvm/Support/DataExtractor.h"
42 #include "llvm/Support/Error.h"
43 #include "llvm/Support/Format.h"
44 #include "llvm/Support/LEB128.h"
45 #include "llvm/Support/MemoryBuffer.h"
46 #include "llvm/Support/Path.h"
47 #include "llvm/Support/TargetRegistry.h"
48 #include "llvm/Support/WithColor.h"
49 #include "llvm/Support/raw_ostream.h"
50 #include <algorithm>
51 #include <cstdint>
52 #include <deque>
53 #include <map>
54 #include <string>
55 #include <utility>
56 #include <vector>
57 
58 using namespace llvm;
59 using namespace dwarf;
60 using namespace object;
61 
62 #define DEBUG_TYPE "dwarf"
63 
64 using DWARFLineTable = DWARFDebugLine::LineTable;
65 using FileLineInfoKind = DILineInfoSpecifier::FileLineInfoKind;
66 using FunctionNameKind = DILineInfoSpecifier::FunctionNameKind;
67 
68 DWARFContext::DWARFContext(std::unique_ptr<const DWARFObject> DObj,
69                            std::string DWPName)
70     : DIContext(CK_DWARF), DWPName(std::move(DWPName)), DObj(std::move(DObj)) {}
71 
72 DWARFContext::~DWARFContext() = default;
73 
74 /// Dump the UUID load command.
75 static void dumpUUID(raw_ostream &OS, const ObjectFile &Obj) {
76   auto *MachO = dyn_cast<MachOObjectFile>(&Obj);
77   if (!MachO)
78     return;
79   for (auto LC : MachO->load_commands()) {
80     raw_ostream::uuid_t UUID;
81     if (LC.C.cmd == MachO::LC_UUID) {
82       if (LC.C.cmdsize < sizeof(UUID) + sizeof(LC.C)) {
83         OS << "error: UUID load command is too short.\n";
84         return;
85       }
86       OS << "UUID: ";
87       memcpy(&UUID, LC.Ptr+sizeof(LC.C), sizeof(UUID));
88       OS.write_uuid(UUID);
89       Triple T = MachO->getArchTriple();
90       OS << " (" << T.getArchName() << ')';
91       OS << ' ' << MachO->getFileName() << '\n';
92     }
93   }
94 }
95 
96 using ContributionCollection =
97     std::vector<Optional<StrOffsetsContributionDescriptor>>;
98 
99 // Collect all the contributions to the string offsets table from all units,
100 // sort them by their starting offsets and remove duplicates.
101 static ContributionCollection
102 collectContributionData(DWARFContext::unit_iterator_range Units) {
103   ContributionCollection Contributions;
104   for (const auto &U : Units)
105     if (const auto &C = U->getStringOffsetsTableContribution())
106       Contributions.push_back(C);
107   // Sort the contributions so that any invalid ones are placed at
108   // the start of the contributions vector. This way they are reported
109   // first.
110   llvm::sort(Contributions,
111              [](const Optional<StrOffsetsContributionDescriptor> &L,
112                 const Optional<StrOffsetsContributionDescriptor> &R) {
113                if (L && R)
114                  return L->Base < R->Base;
115                return R.hasValue();
116              });
117 
118   // Uniquify contributions, as it is possible that units (specifically
119   // type units in dwo or dwp files) share contributions. We don't want
120   // to report them more than once.
121   Contributions.erase(
122       std::unique(Contributions.begin(), Contributions.end(),
123                   [](const Optional<StrOffsetsContributionDescriptor> &L,
124                      const Optional<StrOffsetsContributionDescriptor> &R) {
125                     if (L && R)
126                       return L->Base == R->Base && L->Size == R->Size;
127                     return false;
128                   }),
129       Contributions.end());
130   return Contributions;
131 }
132 
133 static void dumpDWARFv5StringOffsetsSection(
134     raw_ostream &OS, StringRef SectionName, const DWARFObject &Obj,
135     const DWARFSection &StringOffsetsSection, StringRef StringSection,
136     DWARFContext::unit_iterator_range Units, bool LittleEndian) {
137   auto Contributions = collectContributionData(Units);
138   DWARFDataExtractor StrOffsetExt(Obj, StringOffsetsSection, LittleEndian, 0);
139   DataExtractor StrData(StringSection, LittleEndian, 0);
140   uint64_t SectionSize = StringOffsetsSection.Data.size();
141   uint64_t Offset = 0;
142   for (auto &Contribution : Contributions) {
143     // Report an ill-formed contribution.
144     if (!Contribution) {
145       OS << "error: invalid contribution to string offsets table in section ."
146          << SectionName << ".\n";
147       return;
148     }
149 
150     dwarf::DwarfFormat Format = Contribution->getFormat();
151     uint16_t Version = Contribution->getVersion();
152     uint64_t ContributionHeader = Contribution->Base;
153     // In DWARF v5 there is a contribution header that immediately precedes
154     // the string offsets base (the location we have previously retrieved from
155     // the CU DIE's DW_AT_str_offsets attribute). The header is located either
156     // 8 or 16 bytes before the base, depending on the contribution's format.
157     if (Version >= 5)
158       ContributionHeader -= Format == DWARF32 ? 8 : 16;
159 
160     // Detect overlapping contributions.
161     if (Offset > ContributionHeader) {
162       WithColor::error()
163           << "overlapping contributions to string offsets table in section ."
164           << SectionName << ".\n";
165       return;
166     }
167     // Report a gap in the table.
168     if (Offset < ContributionHeader) {
169       OS << format("0x%8.8" PRIx64 ": Gap, length = ", Offset);
170       OS << (ContributionHeader - Offset) << "\n";
171     }
172     OS << format("0x%8.8" PRIx64 ": ", ContributionHeader);
173     // In DWARF v5 the contribution size in the descriptor does not equal
174     // the originally encoded length (it does not contain the length of the
175     // version field and the padding, a total of 4 bytes). Add them back in
176     // for reporting.
177     OS << "Contribution size = " << (Contribution->Size + (Version < 5 ? 0 : 4))
178        << ", Format = " << (Format == DWARF32 ? "DWARF32" : "DWARF64")
179        << ", Version = " << Version << "\n";
180 
181     Offset = Contribution->Base;
182     unsigned EntrySize = Contribution->getDwarfOffsetByteSize();
183     while (Offset - Contribution->Base < Contribution->Size) {
184       OS << format("0x%8.8" PRIx64 ": ", Offset);
185       uint64_t StringOffset =
186           StrOffsetExt.getRelocatedValue(EntrySize, &Offset);
187       OS << format("%8.8" PRIx64 " ", StringOffset);
188       const char *S = StrData.getCStr(&StringOffset);
189       if (S)
190         OS << format("\"%s\"", S);
191       OS << "\n";
192     }
193   }
194   // Report a gap at the end of the table.
195   if (Offset < SectionSize) {
196     OS << format("0x%8.8" PRIx64 ": Gap, length = ", Offset);
197     OS << (SectionSize - Offset) << "\n";
198   }
199 }
200 
201 // Dump a DWARF string offsets section. This may be a DWARF v5 formatted
202 // string offsets section, where each compile or type unit contributes a
203 // number of entries (string offsets), with each contribution preceded by
204 // a header containing size and version number. Alternatively, it may be a
205 // monolithic series of string offsets, as generated by the pre-DWARF v5
206 // implementation of split DWARF.
207 static void dumpStringOffsetsSection(raw_ostream &OS, StringRef SectionName,
208                                      const DWARFObject &Obj,
209                                      const DWARFSection &StringOffsetsSection,
210                                      StringRef StringSection,
211                                      DWARFContext::unit_iterator_range Units,
212                                      bool LittleEndian, unsigned MaxVersion) {
213   // If we have at least one (compile or type) unit with DWARF v5 or greater,
214   // we assume that the section is formatted like a DWARF v5 string offsets
215   // section.
216   if (MaxVersion >= 5)
217     dumpDWARFv5StringOffsetsSection(OS, SectionName, Obj, StringOffsetsSection,
218                                     StringSection, Units, LittleEndian);
219   else {
220     DataExtractor strOffsetExt(StringOffsetsSection.Data, LittleEndian, 0);
221     uint64_t offset = 0;
222     uint64_t size = StringOffsetsSection.Data.size();
223     // Ensure that size is a multiple of the size of an entry.
224     if (size & ((uint64_t)(sizeof(uint32_t) - 1))) {
225       OS << "error: size of ." << SectionName << " is not a multiple of "
226          << sizeof(uint32_t) << ".\n";
227       size &= -(uint64_t)sizeof(uint32_t);
228     }
229     DataExtractor StrData(StringSection, LittleEndian, 0);
230     while (offset < size) {
231       OS << format("0x%8.8" PRIx64 ": ", offset);
232       uint64_t StringOffset = strOffsetExt.getU32(&offset);
233       OS << format("%8.8" PRIx64 "  ", StringOffset);
234       const char *S = StrData.getCStr(&StringOffset);
235       if (S)
236         OS << format("\"%s\"", S);
237       OS << "\n";
238     }
239   }
240 }
241 
242 // Dump the .debug_addr section.
243 static void dumpAddrSection(raw_ostream &OS, DWARFDataExtractor &AddrData,
244                             DIDumpOptions DumpOpts, uint16_t Version,
245                             uint8_t AddrSize) {
246   uint64_t Offset = 0;
247   while (AddrData.isValidOffset(Offset)) {
248     DWARFDebugAddrTable AddrTable;
249     uint64_t TableOffset = Offset;
250     if (Error Err = AddrTable.extract(AddrData, &Offset, Version, AddrSize,
251                                       DWARFContext::dumpWarning)) {
252       WithColor::error() << toString(std::move(Err)) << '\n';
253       // Keep going after an error, if we can, assuming that the length field
254       // could be read. If it couldn't, stop reading the section.
255       if (!AddrTable.hasValidLength())
256         break;
257       Offset = TableOffset + AddrTable.getLength();
258     } else {
259       AddrTable.dump(OS, DumpOpts);
260     }
261   }
262 }
263 
264 // Dump the .debug_rnglists or .debug_rnglists.dwo section (DWARF v5).
265 static void dumpRnglistsSection(
266     raw_ostream &OS, DWARFDataExtractor &rnglistData,
267     llvm::function_ref<Optional<object::SectionedAddress>(uint32_t)>
268         LookupPooledAddress,
269     DIDumpOptions DumpOpts) {
270   uint64_t Offset = 0;
271   while (rnglistData.isValidOffset(Offset)) {
272     llvm::DWARFDebugRnglistTable Rnglists;
273     uint64_t TableOffset = Offset;
274     if (Error Err = Rnglists.extract(rnglistData, &Offset)) {
275       WithColor::error() << toString(std::move(Err)) << '\n';
276       uint64_t Length = Rnglists.length();
277       // Keep going after an error, if we can, assuming that the length field
278       // could be read. If it couldn't, stop reading the section.
279       if (Length == 0)
280         break;
281       Offset = TableOffset + Length;
282     } else {
283       Rnglists.dump(OS, LookupPooledAddress, DumpOpts);
284     }
285   }
286 }
287 
288 static void dumpLoclistsSection(raw_ostream &OS, DIDumpOptions DumpOpts,
289                                 DWARFDataExtractor Data,
290                                 const MCRegisterInfo *MRI,
291                                 Optional<uint64_t> DumpOffset) {
292   uint64_t Offset = 0;
293 
294   while (Data.isValidOffset(Offset)) {
295     DWARFListTableHeader Header(".debug_loclists", "locations");
296     if (Error E = Header.extract(Data, &Offset)) {
297       WithColor::error() << toString(std::move(E)) << '\n';
298       return;
299     }
300 
301     Header.dump(OS, DumpOpts);
302     DataExtractor LocData(Data.getData(),
303                           Data.isLittleEndian(), Header.getAddrSize());
304 
305     DWARFDebugLoclists Loclists;
306     uint64_t EndOffset = Header.length() + Header.getHeaderOffset();
307     Loclists.parse(LocData, Offset, EndOffset, Header.getVersion());
308     Loclists.dump(OS, 0, MRI, DumpOpts, DumpOffset);
309     Offset = EndOffset;
310   }
311 }
312 
313 void DWARFContext::dump(
314     raw_ostream &OS, DIDumpOptions DumpOpts,
315     std::array<Optional<uint64_t>, DIDT_ID_Count> DumpOffsets) {
316 
317   uint64_t DumpType = DumpOpts.DumpType;
318 
319   StringRef Extension = sys::path::extension(DObj->getFileName());
320   bool IsDWO = (Extension == ".dwo") || (Extension == ".dwp");
321 
322   // Print UUID header.
323   const auto *ObjFile = DObj->getFile();
324   if (DumpType & DIDT_UUID)
325     dumpUUID(OS, *ObjFile);
326 
327   // Print a header for each explicitly-requested section.
328   // Otherwise just print one for non-empty sections.
329   // Only print empty .dwo section headers when dumping a .dwo file.
330   bool Explicit = DumpType != DIDT_All && !IsDWO;
331   bool ExplicitDWO = Explicit && IsDWO;
332   auto shouldDump = [&](bool Explicit, const char *Name, unsigned ID,
333                         StringRef Section) -> Optional<uint64_t> * {
334     unsigned Mask = 1U << ID;
335     bool Should = (DumpType & Mask) && (Explicit || !Section.empty());
336     if (!Should)
337       return nullptr;
338     OS << "\n" << Name << " contents:\n";
339     return &DumpOffsets[ID];
340   };
341 
342   // Dump individual sections.
343   if (shouldDump(Explicit, ".debug_abbrev", DIDT_ID_DebugAbbrev,
344                  DObj->getAbbrevSection()))
345     getDebugAbbrev()->dump(OS);
346   if (shouldDump(ExplicitDWO, ".debug_abbrev.dwo", DIDT_ID_DebugAbbrev,
347                  DObj->getAbbrevDWOSection()))
348     getDebugAbbrevDWO()->dump(OS);
349 
350   auto dumpDebugInfo = [&](const char *Name, unit_iterator_range Units) {
351     OS << '\n' << Name << " contents:\n";
352     if (auto DumpOffset = DumpOffsets[DIDT_ID_DebugInfo])
353       for (const auto &U : Units)
354         U->getDIEForOffset(DumpOffset.getValue())
355             .dump(OS, 0, DumpOpts.noImplicitRecursion());
356     else
357       for (const auto &U : Units)
358         U->dump(OS, DumpOpts);
359   };
360   if ((DumpType & DIDT_DebugInfo)) {
361     if (Explicit || getNumCompileUnits())
362       dumpDebugInfo(".debug_info", info_section_units());
363     if (ExplicitDWO || getNumDWOCompileUnits())
364       dumpDebugInfo(".debug_info.dwo", dwo_info_section_units());
365   }
366 
367   auto dumpDebugType = [&](const char *Name, unit_iterator_range Units) {
368     OS << '\n' << Name << " contents:\n";
369     for (const auto &U : Units)
370       if (auto DumpOffset = DumpOffsets[DIDT_ID_DebugTypes])
371         U->getDIEForOffset(*DumpOffset)
372             .dump(OS, 0, DumpOpts.noImplicitRecursion());
373       else
374         U->dump(OS, DumpOpts);
375   };
376   if ((DumpType & DIDT_DebugTypes)) {
377     if (Explicit || getNumTypeUnits())
378       dumpDebugType(".debug_types", types_section_units());
379     if (ExplicitDWO || getNumDWOTypeUnits())
380       dumpDebugType(".debug_types.dwo", dwo_types_section_units());
381   }
382 
383   if (const auto *Off = shouldDump(Explicit, ".debug_loc", DIDT_ID_DebugLoc,
384                                    DObj->getLocSection().Data)) {
385     getDebugLoc()->dump(OS, getRegisterInfo(), DumpOpts, *Off);
386   }
387   if (const auto *Off =
388           shouldDump(Explicit, ".debug_loclists", DIDT_ID_DebugLoclists,
389                      DObj->getLoclistsSection().Data)) {
390     DWARFDataExtractor Data(*DObj, DObj->getLoclistsSection(), isLittleEndian(),
391                             0);
392     dumpLoclistsSection(OS, DumpOpts, Data, getRegisterInfo(), *Off);
393   }
394   if (const auto *Off =
395           shouldDump(ExplicitDWO, ".debug_loc.dwo", DIDT_ID_DebugLoc,
396                      DObj->getLocDWOSection().Data)) {
397     getDebugLocDWO()->dump(OS, 0, getRegisterInfo(), DumpOpts, *Off);
398   }
399 
400   if (const auto *Off = shouldDump(Explicit, ".debug_frame", DIDT_ID_DebugFrame,
401                                    DObj->getFrameSection().Data))
402     getDebugFrame()->dump(OS, getRegisterInfo(), *Off);
403 
404   if (const auto *Off = shouldDump(Explicit, ".eh_frame", DIDT_ID_DebugFrame,
405                                    DObj->getEHFrameSection().Data))
406     getEHFrame()->dump(OS, getRegisterInfo(), *Off);
407 
408   if (DumpType & DIDT_DebugMacro) {
409     if (Explicit || !getDebugMacro()->empty()) {
410       OS << "\n.debug_macinfo contents:\n";
411       getDebugMacro()->dump(OS);
412     }
413   }
414 
415   if (shouldDump(Explicit, ".debug_aranges", DIDT_ID_DebugAranges,
416                  DObj->getArangesSection())) {
417     uint64_t offset = 0;
418     DataExtractor arangesData(DObj->getArangesSection(), isLittleEndian(), 0);
419     DWARFDebugArangeSet set;
420     while (set.extract(arangesData, &offset))
421       set.dump(OS);
422   }
423 
424   auto DumpLineSection = [&](DWARFDebugLine::SectionParser Parser,
425                              DIDumpOptions DumpOpts,
426                              Optional<uint64_t> DumpOffset) {
427     while (!Parser.done()) {
428       if (DumpOffset && Parser.getOffset() != *DumpOffset) {
429         Parser.skip(dumpWarning);
430         continue;
431       }
432       OS << "debug_line[" << format("0x%8.8" PRIx64, Parser.getOffset())
433          << "]\n";
434       if (DumpOpts.Verbose) {
435         Parser.parseNext(dumpWarning, dumpWarning, &OS);
436       } else {
437         DWARFDebugLine::LineTable LineTable =
438             Parser.parseNext(dumpWarning, dumpWarning);
439         LineTable.dump(OS, DumpOpts);
440       }
441     }
442   };
443 
444   if (const auto *Off = shouldDump(Explicit, ".debug_line", DIDT_ID_DebugLine,
445                                    DObj->getLineSection().Data)) {
446     DWARFDataExtractor LineData(*DObj, DObj->getLineSection(), isLittleEndian(),
447                                 0);
448     DWARFDebugLine::SectionParser Parser(LineData, *this, compile_units(),
449                                          type_units());
450     DumpLineSection(Parser, DumpOpts, *Off);
451   }
452 
453   if (const auto *Off =
454           shouldDump(ExplicitDWO, ".debug_line.dwo", DIDT_ID_DebugLine,
455                      DObj->getLineDWOSection().Data)) {
456     DWARFDataExtractor LineData(*DObj, DObj->getLineDWOSection(),
457                                 isLittleEndian(), 0);
458     DWARFDebugLine::SectionParser Parser(LineData, *this, dwo_compile_units(),
459                                          dwo_type_units());
460     DumpLineSection(Parser, DumpOpts, *Off);
461   }
462 
463   if (shouldDump(Explicit, ".debug_cu_index", DIDT_ID_DebugCUIndex,
464                  DObj->getCUIndexSection())) {
465     getCUIndex().dump(OS);
466   }
467 
468   if (shouldDump(Explicit, ".debug_tu_index", DIDT_ID_DebugTUIndex,
469                  DObj->getTUIndexSection())) {
470     getTUIndex().dump(OS);
471   }
472 
473   if (shouldDump(Explicit, ".debug_str", DIDT_ID_DebugStr,
474                  DObj->getStrSection())) {
475     DataExtractor strData(DObj->getStrSection(), isLittleEndian(), 0);
476     uint64_t offset = 0;
477     uint64_t strOffset = 0;
478     while (const char *s = strData.getCStr(&offset)) {
479       OS << format("0x%8.8" PRIx64 ": \"%s\"\n", strOffset, s);
480       strOffset = offset;
481     }
482   }
483   if (shouldDump(ExplicitDWO, ".debug_str.dwo", DIDT_ID_DebugStr,
484                  DObj->getStrDWOSection())) {
485     DataExtractor strDWOData(DObj->getStrDWOSection(), isLittleEndian(), 0);
486     uint64_t offset = 0;
487     uint64_t strDWOOffset = 0;
488     while (const char *s = strDWOData.getCStr(&offset)) {
489       OS << format("0x%8.8" PRIx64 ": \"%s\"\n", strDWOOffset, s);
490       strDWOOffset = offset;
491     }
492   }
493   if (shouldDump(Explicit, ".debug_line_str", DIDT_ID_DebugLineStr,
494                  DObj->getLineStrSection())) {
495     DataExtractor strData(DObj->getLineStrSection(), isLittleEndian(), 0);
496     uint64_t offset = 0;
497     uint64_t strOffset = 0;
498     while (const char *s = strData.getCStr(&offset)) {
499       OS << format("0x%8.8" PRIx64 ": \"", strOffset);
500       OS.write_escaped(s);
501       OS << "\"\n";
502       strOffset = offset;
503     }
504   }
505 
506   if (shouldDump(Explicit, ".debug_addr", DIDT_ID_DebugAddr,
507                  DObj->getAddrSection().Data)) {
508     DWARFDataExtractor AddrData(*DObj, DObj->getAddrSection(),
509                                    isLittleEndian(), 0);
510     dumpAddrSection(OS, AddrData, DumpOpts, getMaxVersion(), getCUAddrSize());
511   }
512 
513   if (shouldDump(Explicit, ".debug_ranges", DIDT_ID_DebugRanges,
514                  DObj->getRangesSection().Data)) {
515     uint8_t savedAddressByteSize = getCUAddrSize();
516     DWARFDataExtractor rangesData(*DObj, DObj->getRangesSection(),
517                                   isLittleEndian(), savedAddressByteSize);
518     uint64_t offset = 0;
519     DWARFDebugRangeList rangeList;
520     while (rangesData.isValidOffset(offset)) {
521       if (Error E = rangeList.extract(rangesData, &offset)) {
522         WithColor::error() << toString(std::move(E)) << '\n';
523         break;
524       }
525       rangeList.dump(OS);
526     }
527   }
528 
529   auto LookupPooledAddress = [&](uint32_t Index) -> Optional<SectionedAddress> {
530     const auto &CUs = compile_units();
531     auto I = CUs.begin();
532     if (I == CUs.end())
533       return None;
534     return (*I)->getAddrOffsetSectionItem(Index);
535   };
536 
537   if (shouldDump(Explicit, ".debug_rnglists", DIDT_ID_DebugRnglists,
538                  DObj->getRnglistsSection().Data)) {
539     DWARFDataExtractor RnglistData(*DObj, DObj->getRnglistsSection(),
540                                    isLittleEndian(), 0);
541     dumpRnglistsSection(OS, RnglistData, LookupPooledAddress, DumpOpts);
542   }
543 
544   if (shouldDump(ExplicitDWO, ".debug_rnglists.dwo", DIDT_ID_DebugRnglists,
545                  DObj->getRnglistsDWOSection().Data)) {
546     DWARFDataExtractor RnglistData(*DObj, DObj->getRnglistsDWOSection(),
547                                    isLittleEndian(), 0);
548     dumpRnglistsSection(OS, RnglistData, LookupPooledAddress, DumpOpts);
549   }
550 
551   if (shouldDump(Explicit, ".debug_pubnames", DIDT_ID_DebugPubnames,
552                  DObj->getPubnamesSection().Data))
553     DWARFDebugPubTable(*DObj, DObj->getPubnamesSection(), isLittleEndian(), false)
554         .dump(OS);
555 
556   if (shouldDump(Explicit, ".debug_pubtypes", DIDT_ID_DebugPubtypes,
557                  DObj->getPubtypesSection().Data))
558     DWARFDebugPubTable(*DObj, DObj->getPubtypesSection(), isLittleEndian(), false)
559         .dump(OS);
560 
561   if (shouldDump(Explicit, ".debug_gnu_pubnames", DIDT_ID_DebugGnuPubnames,
562                  DObj->getGnuPubnamesSection().Data))
563     DWARFDebugPubTable(*DObj, DObj->getGnuPubnamesSection(), isLittleEndian(),
564                        true /* GnuStyle */)
565         .dump(OS);
566 
567   if (shouldDump(Explicit, ".debug_gnu_pubtypes", DIDT_ID_DebugGnuPubtypes,
568                  DObj->getGnuPubtypesSection().Data))
569     DWARFDebugPubTable(*DObj, DObj->getGnuPubtypesSection(), isLittleEndian(),
570                        true /* GnuStyle */)
571         .dump(OS);
572 
573   if (shouldDump(Explicit, ".debug_str_offsets", DIDT_ID_DebugStrOffsets,
574                  DObj->getStrOffsetsSection().Data))
575     dumpStringOffsetsSection(OS, "debug_str_offsets", *DObj,
576                              DObj->getStrOffsetsSection(),
577                              DObj->getStrSection(), normal_units(),
578                              isLittleEndian(), getMaxVersion());
579   if (shouldDump(ExplicitDWO, ".debug_str_offsets.dwo", DIDT_ID_DebugStrOffsets,
580                  DObj->getStrOffsetsDWOSection().Data))
581     dumpStringOffsetsSection(OS, "debug_str_offsets.dwo", *DObj,
582                              DObj->getStrOffsetsDWOSection(),
583                              DObj->getStrDWOSection(), dwo_units(),
584                              isLittleEndian(), getMaxDWOVersion());
585 
586   if (shouldDump(Explicit, ".gdb_index", DIDT_ID_GdbIndex,
587                  DObj->getGdbIndexSection())) {
588     getGdbIndex().dump(OS);
589   }
590 
591   if (shouldDump(Explicit, ".apple_names", DIDT_ID_AppleNames,
592                  DObj->getAppleNamesSection().Data))
593     getAppleNames().dump(OS);
594 
595   if (shouldDump(Explicit, ".apple_types", DIDT_ID_AppleTypes,
596                  DObj->getAppleTypesSection().Data))
597     getAppleTypes().dump(OS);
598 
599   if (shouldDump(Explicit, ".apple_namespaces", DIDT_ID_AppleNamespaces,
600                  DObj->getAppleNamespacesSection().Data))
601     getAppleNamespaces().dump(OS);
602 
603   if (shouldDump(Explicit, ".apple_objc", DIDT_ID_AppleObjC,
604                  DObj->getAppleObjCSection().Data))
605     getAppleObjC().dump(OS);
606   if (shouldDump(Explicit, ".debug_names", DIDT_ID_DebugNames,
607                  DObj->getNamesSection().Data))
608     getDebugNames().dump(OS);
609 }
610 
611 DWARFCompileUnit *DWARFContext::getDWOCompileUnitForHash(uint64_t Hash) {
612   parseDWOUnits(LazyParse);
613 
614   if (const auto &CUI = getCUIndex()) {
615     if (const auto *R = CUI.getFromHash(Hash))
616       return dyn_cast_or_null<DWARFCompileUnit>(
617           DWOUnits.getUnitForIndexEntry(*R));
618     return nullptr;
619   }
620 
621   // If there's no index, just search through the CUs in the DWO - there's
622   // probably only one unless this is something like LTO - though an in-process
623   // built/cached lookup table could be used in that case to improve repeated
624   // lookups of different CUs in the DWO.
625   for (const auto &DWOCU : dwo_compile_units()) {
626     // Might not have parsed DWO ID yet.
627     if (!DWOCU->getDWOId()) {
628       if (Optional<uint64_t> DWOId =
629           toUnsigned(DWOCU->getUnitDIE().find(DW_AT_GNU_dwo_id)))
630         DWOCU->setDWOId(*DWOId);
631       else
632         // No DWO ID?
633         continue;
634     }
635     if (DWOCU->getDWOId() == Hash)
636       return dyn_cast<DWARFCompileUnit>(DWOCU.get());
637   }
638   return nullptr;
639 }
640 
641 DWARFDie DWARFContext::getDIEForOffset(uint64_t Offset) {
642   parseNormalUnits();
643   if (auto *CU = NormalUnits.getUnitForOffset(Offset))
644     return CU->getDIEForOffset(Offset);
645   return DWARFDie();
646 }
647 
648 bool DWARFContext::verify(raw_ostream &OS, DIDumpOptions DumpOpts) {
649   bool Success = true;
650   DWARFVerifier verifier(OS, *this, DumpOpts);
651 
652   Success &= verifier.handleDebugAbbrev();
653   if (DumpOpts.DumpType & DIDT_DebugInfo)
654     Success &= verifier.handleDebugInfo();
655   if (DumpOpts.DumpType & DIDT_DebugLine)
656     Success &= verifier.handleDebugLine();
657   Success &= verifier.handleAccelTables();
658   return Success;
659 }
660 
661 const DWARFUnitIndex &DWARFContext::getCUIndex() {
662   if (CUIndex)
663     return *CUIndex;
664 
665   DataExtractor CUIndexData(DObj->getCUIndexSection(), isLittleEndian(), 0);
666 
667   CUIndex = std::make_unique<DWARFUnitIndex>(DW_SECT_INFO);
668   CUIndex->parse(CUIndexData);
669   return *CUIndex;
670 }
671 
672 const DWARFUnitIndex &DWARFContext::getTUIndex() {
673   if (TUIndex)
674     return *TUIndex;
675 
676   DataExtractor TUIndexData(DObj->getTUIndexSection(), isLittleEndian(), 0);
677 
678   TUIndex = std::make_unique<DWARFUnitIndex>(DW_SECT_TYPES);
679   TUIndex->parse(TUIndexData);
680   return *TUIndex;
681 }
682 
683 DWARFGdbIndex &DWARFContext::getGdbIndex() {
684   if (GdbIndex)
685     return *GdbIndex;
686 
687   DataExtractor GdbIndexData(DObj->getGdbIndexSection(), true /*LE*/, 0);
688   GdbIndex = std::make_unique<DWARFGdbIndex>();
689   GdbIndex->parse(GdbIndexData);
690   return *GdbIndex;
691 }
692 
693 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
694   if (Abbrev)
695     return Abbrev.get();
696 
697   DataExtractor abbrData(DObj->getAbbrevSection(), isLittleEndian(), 0);
698 
699   Abbrev.reset(new DWARFDebugAbbrev());
700   Abbrev->extract(abbrData);
701   return Abbrev.get();
702 }
703 
704 const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
705   if (AbbrevDWO)
706     return AbbrevDWO.get();
707 
708   DataExtractor abbrData(DObj->getAbbrevDWOSection(), isLittleEndian(), 0);
709   AbbrevDWO.reset(new DWARFDebugAbbrev());
710   AbbrevDWO->extract(abbrData);
711   return AbbrevDWO.get();
712 }
713 
714 const DWARFDebugLoc *DWARFContext::getDebugLoc() {
715   if (Loc)
716     return Loc.get();
717 
718   Loc.reset(new DWARFDebugLoc);
719   // Assume all units have the same address byte size.
720   if (getNumCompileUnits()) {
721     DWARFDataExtractor LocData(*DObj, DObj->getLocSection(), isLittleEndian(),
722                                getUnitAtIndex(0)->getAddressByteSize());
723     Loc->parse(LocData);
724   }
725   return Loc.get();
726 }
727 
728 const DWARFDebugLoclists *DWARFContext::getDebugLocDWO() {
729   if (LocDWO)
730     return LocDWO.get();
731 
732   LocDWO.reset(new DWARFDebugLoclists());
733   // Assume all compile units have the same address byte size.
734   // FIXME: We don't need AddressSize for split DWARF since relocatable
735   // addresses cannot appear there. At the moment DWARFExpression requires it.
736   DataExtractor LocData(DObj->getLocDWOSection().Data, isLittleEndian(), 4);
737   // Use version 4. DWO does not support the DWARF v5 .debug_loclists yet and
738   // that means we are parsing the new style .debug_loc (pre-standatized version
739   // of the .debug_loclists).
740   LocDWO->parse(LocData, 0, LocData.getData().size(), 4 /* Version */);
741   return LocDWO.get();
742 }
743 
744 const DWARFDebugAranges *DWARFContext::getDebugAranges() {
745   if (Aranges)
746     return Aranges.get();
747 
748   Aranges.reset(new DWARFDebugAranges());
749   Aranges->generate(this);
750   return Aranges.get();
751 }
752 
753 const DWARFDebugFrame *DWARFContext::getDebugFrame() {
754   if (DebugFrame)
755     return DebugFrame.get();
756 
757   // There's a "bug" in the DWARFv3 standard with respect to the target address
758   // size within debug frame sections. While DWARF is supposed to be independent
759   // of its container, FDEs have fields with size being "target address size",
760   // which isn't specified in DWARF in general. It's only specified for CUs, but
761   // .eh_frame can appear without a .debug_info section. Follow the example of
762   // other tools (libdwarf) and extract this from the container (ObjectFile
763   // provides this information). This problem is fixed in DWARFv4
764   // See this dwarf-discuss discussion for more details:
765   // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
766   DWARFDataExtractor debugFrameData(*DObj, DObj->getFrameSection(),
767                                     isLittleEndian(), DObj->getAddressSize());
768   DebugFrame.reset(new DWARFDebugFrame(getArch(), false /* IsEH */));
769   DebugFrame->parse(debugFrameData);
770   return DebugFrame.get();
771 }
772 
773 const DWARFDebugFrame *DWARFContext::getEHFrame() {
774   if (EHFrame)
775     return EHFrame.get();
776 
777   DWARFDataExtractor debugFrameData(*DObj, DObj->getEHFrameSection(),
778                                     isLittleEndian(), DObj->getAddressSize());
779   DebugFrame.reset(new DWARFDebugFrame(getArch(), true /* IsEH */));
780   DebugFrame->parse(debugFrameData);
781   return DebugFrame.get();
782 }
783 
784 const DWARFDebugMacro *DWARFContext::getDebugMacro() {
785   if (Macro)
786     return Macro.get();
787 
788   DataExtractor MacinfoData(DObj->getMacinfoSection(), isLittleEndian(), 0);
789   Macro.reset(new DWARFDebugMacro());
790   Macro->parse(MacinfoData);
791   return Macro.get();
792 }
793 
794 template <typename T>
795 static T &getAccelTable(std::unique_ptr<T> &Cache, const DWARFObject &Obj,
796                         const DWARFSection &Section, StringRef StringSection,
797                         bool IsLittleEndian) {
798   if (Cache)
799     return *Cache;
800   DWARFDataExtractor AccelSection(Obj, Section, IsLittleEndian, 0);
801   DataExtractor StrData(StringSection, IsLittleEndian, 0);
802   Cache.reset(new T(AccelSection, StrData));
803   if (Error E = Cache->extract())
804     llvm::consumeError(std::move(E));
805   return *Cache;
806 }
807 
808 const DWARFDebugNames &DWARFContext::getDebugNames() {
809   return getAccelTable(Names, *DObj, DObj->getNamesSection(),
810                        DObj->getStrSection(), isLittleEndian());
811 }
812 
813 const AppleAcceleratorTable &DWARFContext::getAppleNames() {
814   return getAccelTable(AppleNames, *DObj, DObj->getAppleNamesSection(),
815                        DObj->getStrSection(), isLittleEndian());
816 }
817 
818 const AppleAcceleratorTable &DWARFContext::getAppleTypes() {
819   return getAccelTable(AppleTypes, *DObj, DObj->getAppleTypesSection(),
820                        DObj->getStrSection(), isLittleEndian());
821 }
822 
823 const AppleAcceleratorTable &DWARFContext::getAppleNamespaces() {
824   return getAccelTable(AppleNamespaces, *DObj,
825                        DObj->getAppleNamespacesSection(),
826                        DObj->getStrSection(), isLittleEndian());
827 }
828 
829 const AppleAcceleratorTable &DWARFContext::getAppleObjC() {
830   return getAccelTable(AppleObjC, *DObj, DObj->getAppleObjCSection(),
831                        DObj->getStrSection(), isLittleEndian());
832 }
833 
834 const DWARFDebugLine::LineTable *
835 DWARFContext::getLineTableForUnit(DWARFUnit *U) {
836   Expected<const DWARFDebugLine::LineTable *> ExpectedLineTable =
837       getLineTableForUnit(U, dumpWarning);
838   if (!ExpectedLineTable) {
839     dumpWarning(ExpectedLineTable.takeError());
840     return nullptr;
841   }
842   return *ExpectedLineTable;
843 }
844 
845 Expected<const DWARFDebugLine::LineTable *> DWARFContext::getLineTableForUnit(
846     DWARFUnit *U, std::function<void(Error)> RecoverableErrorCallback) {
847   if (!Line)
848     Line.reset(new DWARFDebugLine);
849 
850   auto UnitDIE = U->getUnitDIE();
851   if (!UnitDIE)
852     return nullptr;
853 
854   auto Offset = toSectionOffset(UnitDIE.find(DW_AT_stmt_list));
855   if (!Offset)
856     return nullptr; // No line table for this compile unit.
857 
858   uint64_t stmtOffset = *Offset + U->getLineTableOffset();
859   // See if the line table is cached.
860   if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
861     return lt;
862 
863   // Make sure the offset is good before we try to parse.
864   if (stmtOffset >= U->getLineSection().Data.size())
865     return nullptr;
866 
867   // We have to parse it first.
868   DWARFDataExtractor lineData(*DObj, U->getLineSection(), isLittleEndian(),
869                               U->getAddressByteSize());
870   return Line->getOrParseLineTable(lineData, stmtOffset, *this, U,
871                                    RecoverableErrorCallback);
872 }
873 
874 void DWARFContext::parseNormalUnits() {
875   if (!NormalUnits.empty())
876     return;
877   DObj->forEachInfoSections([&](const DWARFSection &S) {
878     NormalUnits.addUnitsForSection(*this, S, DW_SECT_INFO);
879   });
880   NormalUnits.finishedInfoUnits();
881   DObj->forEachTypesSections([&](const DWARFSection &S) {
882     NormalUnits.addUnitsForSection(*this, S, DW_SECT_TYPES);
883   });
884 }
885 
886 void DWARFContext::parseDWOUnits(bool Lazy) {
887   if (!DWOUnits.empty())
888     return;
889   DObj->forEachInfoDWOSections([&](const DWARFSection &S) {
890     DWOUnits.addUnitsForDWOSection(*this, S, DW_SECT_INFO, Lazy);
891   });
892   DWOUnits.finishedInfoUnits();
893   DObj->forEachTypesDWOSections([&](const DWARFSection &S) {
894     DWOUnits.addUnitsForDWOSection(*this, S, DW_SECT_TYPES, Lazy);
895   });
896 }
897 
898 DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint64_t Offset) {
899   parseNormalUnits();
900   return dyn_cast_or_null<DWARFCompileUnit>(
901       NormalUnits.getUnitForOffset(Offset));
902 }
903 
904 DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
905   // First, get the offset of the compile unit.
906   uint64_t CUOffset = getDebugAranges()->findAddress(Address);
907   // Retrieve the compile unit.
908   return getCompileUnitForOffset(CUOffset);
909 }
910 
911 DWARFContext::DIEsForAddress DWARFContext::getDIEsForAddress(uint64_t Address) {
912   DIEsForAddress Result;
913 
914   DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
915   if (!CU)
916     return Result;
917 
918   Result.CompileUnit = CU;
919   Result.FunctionDIE = CU->getSubroutineForAddress(Address);
920 
921   std::vector<DWARFDie> Worklist;
922   Worklist.push_back(Result.FunctionDIE);
923   while (!Worklist.empty()) {
924     DWARFDie DIE = Worklist.back();
925     Worklist.pop_back();
926 
927     if (!DIE.isValid())
928       continue;
929 
930     if (DIE.getTag() == DW_TAG_lexical_block &&
931         DIE.addressRangeContainsAddress(Address)) {
932       Result.BlockDIE = DIE;
933       break;
934     }
935 
936     for (auto Child : DIE)
937       Worklist.push_back(Child);
938   }
939 
940   return Result;
941 }
942 
943 /// TODO: change input parameter from "uint64_t Address"
944 ///       into "SectionedAddress Address"
945 static bool getFunctionNameAndStartLineForAddress(DWARFCompileUnit *CU,
946                                                   uint64_t Address,
947                                                   FunctionNameKind Kind,
948                                                   std::string &FunctionName,
949                                                   uint32_t &StartLine) {
950   // The address may correspond to instruction in some inlined function,
951   // so we have to build the chain of inlined functions and take the
952   // name of the topmost function in it.
953   SmallVector<DWARFDie, 4> InlinedChain;
954   CU->getInlinedChainForAddress(Address, InlinedChain);
955   if (InlinedChain.empty())
956     return false;
957 
958   const DWARFDie &DIE = InlinedChain[0];
959   bool FoundResult = false;
960   const char *Name = nullptr;
961   if (Kind != FunctionNameKind::None && (Name = DIE.getSubroutineName(Kind))) {
962     FunctionName = Name;
963     FoundResult = true;
964   }
965   if (auto DeclLineResult = DIE.getDeclLine()) {
966     StartLine = DeclLineResult;
967     FoundResult = true;
968   }
969 
970   return FoundResult;
971 }
972 
973 static Optional<uint64_t> getTypeSize(DWARFDie Type, uint64_t PointerSize) {
974   if (auto SizeAttr = Type.find(DW_AT_byte_size))
975     if (Optional<uint64_t> Size = SizeAttr->getAsUnsignedConstant())
976       return Size;
977 
978   switch (Type.getTag()) {
979   case DW_TAG_pointer_type:
980   case DW_TAG_reference_type:
981   case DW_TAG_rvalue_reference_type:
982     return PointerSize;
983   case DW_TAG_ptr_to_member_type: {
984     if (DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type))
985       if (BaseType.getTag() == DW_TAG_subroutine_type)
986         return 2 * PointerSize;
987     return PointerSize;
988   }
989   case DW_TAG_const_type:
990   case DW_TAG_volatile_type:
991   case DW_TAG_restrict_type:
992   case DW_TAG_typedef: {
993     if (DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type))
994       return getTypeSize(BaseType, PointerSize);
995     break;
996   }
997   case DW_TAG_array_type: {
998     DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type);
999     if (!BaseType)
1000       return Optional<uint64_t>();
1001     Optional<uint64_t> BaseSize = getTypeSize(BaseType, PointerSize);
1002     if (!BaseSize)
1003       return Optional<uint64_t>();
1004     uint64_t Size = *BaseSize;
1005     for (DWARFDie Child : Type) {
1006       if (Child.getTag() != DW_TAG_subrange_type)
1007         continue;
1008 
1009       if (auto ElemCountAttr = Child.find(DW_AT_count))
1010         if (Optional<uint64_t> ElemCount =
1011                 ElemCountAttr->getAsUnsignedConstant())
1012           Size *= *ElemCount;
1013       if (auto UpperBoundAttr = Child.find(DW_AT_upper_bound))
1014         if (Optional<int64_t> UpperBound =
1015                 UpperBoundAttr->getAsSignedConstant()) {
1016           int64_t LowerBound = 0;
1017           if (auto LowerBoundAttr = Child.find(DW_AT_lower_bound))
1018             LowerBound = LowerBoundAttr->getAsSignedConstant().getValueOr(0);
1019           Size *= *UpperBound - LowerBound + 1;
1020         }
1021     }
1022     return Size;
1023   }
1024   default:
1025     break;
1026   }
1027   return Optional<uint64_t>();
1028 }
1029 
1030 void DWARFContext::addLocalsForDie(DWARFCompileUnit *CU, DWARFDie Subprogram,
1031                                    DWARFDie Die, std::vector<DILocal> &Result) {
1032   if (Die.getTag() == DW_TAG_variable ||
1033       Die.getTag() == DW_TAG_formal_parameter) {
1034     DILocal Local;
1035     if (auto NameAttr = Subprogram.find(DW_AT_name))
1036       if (Optional<const char *> Name = NameAttr->getAsCString())
1037         Local.FunctionName = *Name;
1038     if (auto LocationAttr = Die.find(DW_AT_location))
1039       if (Optional<ArrayRef<uint8_t>> Location = LocationAttr->getAsBlock())
1040         if (!Location->empty() && (*Location)[0] == DW_OP_fbreg)
1041           Local.FrameOffset =
1042               decodeSLEB128(Location->data() + 1, nullptr, Location->end());
1043     if (auto TagOffsetAttr = Die.find(DW_AT_LLVM_tag_offset))
1044       Local.TagOffset = TagOffsetAttr->getAsUnsignedConstant();
1045 
1046     if (auto Origin =
1047             Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
1048       Die = Origin;
1049     if (auto NameAttr = Die.find(DW_AT_name))
1050       if (Optional<const char *> Name = NameAttr->getAsCString())
1051         Local.Name = *Name;
1052     if (auto Type = Die.getAttributeValueAsReferencedDie(DW_AT_type))
1053       Local.Size = getTypeSize(Type, getCUAddrSize());
1054     if (auto DeclFileAttr = Die.find(DW_AT_decl_file)) {
1055       if (const auto *LT = CU->getContext().getLineTableForUnit(CU))
1056         LT->getFileNameByIndex(
1057             DeclFileAttr->getAsUnsignedConstant().getValue(),
1058             CU->getCompilationDir(),
1059             DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
1060             Local.DeclFile);
1061     }
1062     if (auto DeclLineAttr = Die.find(DW_AT_decl_line))
1063       Local.DeclLine = DeclLineAttr->getAsUnsignedConstant().getValue();
1064 
1065     Result.push_back(Local);
1066     return;
1067   }
1068 
1069   if (Die.getTag() == DW_TAG_inlined_subroutine)
1070     if (auto Origin =
1071             Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
1072       Subprogram = Origin;
1073 
1074   for (auto Child : Die)
1075     addLocalsForDie(CU, Subprogram, Child, Result);
1076 }
1077 
1078 std::vector<DILocal>
1079 DWARFContext::getLocalsForAddress(object::SectionedAddress Address) {
1080   std::vector<DILocal> Result;
1081   DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
1082   if (!CU)
1083     return Result;
1084 
1085   DWARFDie Subprogram = CU->getSubroutineForAddress(Address.Address);
1086   if (Subprogram.isValid())
1087     addLocalsForDie(CU, Subprogram, Subprogram, Result);
1088   return Result;
1089 }
1090 
1091 DILineInfo DWARFContext::getLineInfoForAddress(object::SectionedAddress Address,
1092                                                DILineInfoSpecifier Spec) {
1093   DILineInfo Result;
1094 
1095   DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
1096   if (!CU)
1097     return Result;
1098 
1099   getFunctionNameAndStartLineForAddress(CU, Address.Address, Spec.FNKind,
1100                                         Result.FunctionName, Result.StartLine);
1101   if (Spec.FLIKind != FileLineInfoKind::None) {
1102     if (const DWARFLineTable *LineTable = getLineTableForUnit(CU)) {
1103       LineTable->getFileLineInfoForAddress(
1104           {Address.Address, Address.SectionIndex}, CU->getCompilationDir(),
1105           Spec.FLIKind, Result);
1106     }
1107   }
1108   return Result;
1109 }
1110 
1111 DILineInfoTable DWARFContext::getLineInfoForAddressRange(
1112     object::SectionedAddress Address, uint64_t Size, DILineInfoSpecifier Spec) {
1113   DILineInfoTable  Lines;
1114   DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
1115   if (!CU)
1116     return Lines;
1117 
1118   uint32_t StartLine = 0;
1119   std::string FunctionName(DILineInfo::BadString);
1120   getFunctionNameAndStartLineForAddress(CU, Address.Address, Spec.FNKind,
1121                                         FunctionName, StartLine);
1122 
1123   // If the Specifier says we don't need FileLineInfo, just
1124   // return the top-most function at the starting address.
1125   if (Spec.FLIKind == FileLineInfoKind::None) {
1126     DILineInfo Result;
1127     Result.FunctionName = FunctionName;
1128     Result.StartLine = StartLine;
1129     Lines.push_back(std::make_pair(Address.Address, Result));
1130     return Lines;
1131   }
1132 
1133   const DWARFLineTable *LineTable = getLineTableForUnit(CU);
1134 
1135   // Get the index of row we're looking for in the line table.
1136   std::vector<uint32_t> RowVector;
1137   if (!LineTable->lookupAddressRange({Address.Address, Address.SectionIndex},
1138                                      Size, RowVector)) {
1139     return Lines;
1140   }
1141 
1142   for (uint32_t RowIndex : RowVector) {
1143     // Take file number and line/column from the row.
1144     const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
1145     DILineInfo Result;
1146     LineTable->getFileNameByIndex(Row.File, CU->getCompilationDir(),
1147                                   Spec.FLIKind, Result.FileName);
1148     Result.FunctionName = FunctionName;
1149     Result.Line = Row.Line;
1150     Result.Column = Row.Column;
1151     Result.StartLine = StartLine;
1152     Lines.push_back(std::make_pair(Row.Address.Address, Result));
1153   }
1154 
1155   return Lines;
1156 }
1157 
1158 DIInliningInfo
1159 DWARFContext::getInliningInfoForAddress(object::SectionedAddress Address,
1160                                         DILineInfoSpecifier Spec) {
1161   DIInliningInfo InliningInfo;
1162 
1163   DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
1164   if (!CU)
1165     return InliningInfo;
1166 
1167   const DWARFLineTable *LineTable = nullptr;
1168   SmallVector<DWARFDie, 4> InlinedChain;
1169   CU->getInlinedChainForAddress(Address.Address, InlinedChain);
1170   if (InlinedChain.size() == 0) {
1171     // If there is no DIE for address (e.g. it is in unavailable .dwo file),
1172     // try to at least get file/line info from symbol table.
1173     if (Spec.FLIKind != FileLineInfoKind::None) {
1174       DILineInfo Frame;
1175       LineTable = getLineTableForUnit(CU);
1176       if (LineTable && LineTable->getFileLineInfoForAddress(
1177                            {Address.Address, Address.SectionIndex},
1178                            CU->getCompilationDir(), Spec.FLIKind, Frame))
1179         InliningInfo.addFrame(Frame);
1180     }
1181     return InliningInfo;
1182   }
1183 
1184   uint32_t CallFile = 0, CallLine = 0, CallColumn = 0, CallDiscriminator = 0;
1185   for (uint32_t i = 0, n = InlinedChain.size(); i != n; i++) {
1186     DWARFDie &FunctionDIE = InlinedChain[i];
1187     DILineInfo Frame;
1188     // Get function name if necessary.
1189     if (const char *Name = FunctionDIE.getSubroutineName(Spec.FNKind))
1190       Frame.FunctionName = Name;
1191     if (auto DeclLineResult = FunctionDIE.getDeclLine())
1192       Frame.StartLine = DeclLineResult;
1193     if (Spec.FLIKind != FileLineInfoKind::None) {
1194       if (i == 0) {
1195         // For the topmost frame, initialize the line table of this
1196         // compile unit and fetch file/line info from it.
1197         LineTable = getLineTableForUnit(CU);
1198         // For the topmost routine, get file/line info from line table.
1199         if (LineTable)
1200           LineTable->getFileLineInfoForAddress(
1201               {Address.Address, Address.SectionIndex}, CU->getCompilationDir(),
1202               Spec.FLIKind, Frame);
1203       } else {
1204         // Otherwise, use call file, call line and call column from
1205         // previous DIE in inlined chain.
1206         if (LineTable)
1207           LineTable->getFileNameByIndex(CallFile, CU->getCompilationDir(),
1208                                         Spec.FLIKind, Frame.FileName);
1209         Frame.Line = CallLine;
1210         Frame.Column = CallColumn;
1211         Frame.Discriminator = CallDiscriminator;
1212       }
1213       // Get call file/line/column of a current DIE.
1214       if (i + 1 < n) {
1215         FunctionDIE.getCallerFrame(CallFile, CallLine, CallColumn,
1216                                    CallDiscriminator);
1217       }
1218     }
1219     InliningInfo.addFrame(Frame);
1220   }
1221   return InliningInfo;
1222 }
1223 
1224 std::shared_ptr<DWARFContext>
1225 DWARFContext::getDWOContext(StringRef AbsolutePath) {
1226   if (auto S = DWP.lock()) {
1227     DWARFContext *Ctxt = S->Context.get();
1228     return std::shared_ptr<DWARFContext>(std::move(S), Ctxt);
1229   }
1230 
1231   std::weak_ptr<DWOFile> *Entry = &DWOFiles[AbsolutePath];
1232 
1233   if (auto S = Entry->lock()) {
1234     DWARFContext *Ctxt = S->Context.get();
1235     return std::shared_ptr<DWARFContext>(std::move(S), Ctxt);
1236   }
1237 
1238   Expected<OwningBinary<ObjectFile>> Obj = [&] {
1239     if (!CheckedForDWP) {
1240       SmallString<128> DWPName;
1241       auto Obj = object::ObjectFile::createObjectFile(
1242           this->DWPName.empty()
1243               ? (DObj->getFileName() + ".dwp").toStringRef(DWPName)
1244               : StringRef(this->DWPName));
1245       if (Obj) {
1246         Entry = &DWP;
1247         return Obj;
1248       } else {
1249         CheckedForDWP = true;
1250         // TODO: Should this error be handled (maybe in a high verbosity mode)
1251         // before falling back to .dwo files?
1252         consumeError(Obj.takeError());
1253       }
1254     }
1255 
1256     return object::ObjectFile::createObjectFile(AbsolutePath);
1257   }();
1258 
1259   if (!Obj) {
1260     // TODO: Actually report errors helpfully.
1261     consumeError(Obj.takeError());
1262     return nullptr;
1263   }
1264 
1265   auto S = std::make_shared<DWOFile>();
1266   S->File = std::move(Obj.get());
1267   S->Context = DWARFContext::create(*S->File.getBinary());
1268   *Entry = S;
1269   auto *Ctxt = S->Context.get();
1270   return std::shared_ptr<DWARFContext>(std::move(S), Ctxt);
1271 }
1272 
1273 static Error createError(const Twine &Reason, llvm::Error E) {
1274   return make_error<StringError>(Reason + toString(std::move(E)),
1275                                  inconvertibleErrorCode());
1276 }
1277 
1278 /// SymInfo contains information about symbol: it's address
1279 /// and section index which is -1LL for absolute symbols.
1280 struct SymInfo {
1281   uint64_t Address;
1282   uint64_t SectionIndex;
1283 };
1284 
1285 /// Returns the address of symbol relocation used against and a section index.
1286 /// Used for futher relocations computation. Symbol's section load address is
1287 static Expected<SymInfo> getSymbolInfo(const object::ObjectFile &Obj,
1288                                        const RelocationRef &Reloc,
1289                                        const LoadedObjectInfo *L,
1290                                        std::map<SymbolRef, SymInfo> &Cache) {
1291   SymInfo Ret = {0, (uint64_t)-1LL};
1292   object::section_iterator RSec = Obj.section_end();
1293   object::symbol_iterator Sym = Reloc.getSymbol();
1294 
1295   std::map<SymbolRef, SymInfo>::iterator CacheIt = Cache.end();
1296   // First calculate the address of the symbol or section as it appears
1297   // in the object file
1298   if (Sym != Obj.symbol_end()) {
1299     bool New;
1300     std::tie(CacheIt, New) = Cache.insert({*Sym, {0, 0}});
1301     if (!New)
1302       return CacheIt->second;
1303 
1304     Expected<uint64_t> SymAddrOrErr = Sym->getAddress();
1305     if (!SymAddrOrErr)
1306       return createError("failed to compute symbol address: ",
1307                          SymAddrOrErr.takeError());
1308 
1309     // Also remember what section this symbol is in for later
1310     auto SectOrErr = Sym->getSection();
1311     if (!SectOrErr)
1312       return createError("failed to get symbol section: ",
1313                          SectOrErr.takeError());
1314 
1315     RSec = *SectOrErr;
1316     Ret.Address = *SymAddrOrErr;
1317   } else if (auto *MObj = dyn_cast<MachOObjectFile>(&Obj)) {
1318     RSec = MObj->getRelocationSection(Reloc.getRawDataRefImpl());
1319     Ret.Address = RSec->getAddress();
1320   }
1321 
1322   if (RSec != Obj.section_end())
1323     Ret.SectionIndex = RSec->getIndex();
1324 
1325   // If we are given load addresses for the sections, we need to adjust:
1326   // SymAddr = (Address of Symbol Or Section in File) -
1327   //           (Address of Section in File) +
1328   //           (Load Address of Section)
1329   // RSec is now either the section being targeted or the section
1330   // containing the symbol being targeted. In either case,
1331   // we need to perform the same computation.
1332   if (L && RSec != Obj.section_end())
1333     if (uint64_t SectionLoadAddress = L->getSectionLoadAddress(*RSec))
1334       Ret.Address += SectionLoadAddress - RSec->getAddress();
1335 
1336   if (CacheIt != Cache.end())
1337     CacheIt->second = Ret;
1338 
1339   return Ret;
1340 }
1341 
1342 static bool isRelocScattered(const object::ObjectFile &Obj,
1343                              const RelocationRef &Reloc) {
1344   const MachOObjectFile *MachObj = dyn_cast<MachOObjectFile>(&Obj);
1345   if (!MachObj)
1346     return false;
1347   // MachO also has relocations that point to sections and
1348   // scattered relocations.
1349   auto RelocInfo = MachObj->getRelocation(Reloc.getRawDataRefImpl());
1350   return MachObj->isRelocationScattered(RelocInfo);
1351 }
1352 
1353 ErrorPolicy DWARFContext::defaultErrorHandler(Error E) {
1354   WithColor::error() << toString(std::move(E)) << '\n';
1355   return ErrorPolicy::Continue;
1356 }
1357 
1358 namespace {
1359 struct DWARFSectionMap final : public DWARFSection {
1360   RelocAddrMap Relocs;
1361 };
1362 
1363 class DWARFObjInMemory final : public DWARFObject {
1364   bool IsLittleEndian;
1365   uint8_t AddressSize;
1366   StringRef FileName;
1367   const object::ObjectFile *Obj = nullptr;
1368   std::vector<SectionName> SectionNames;
1369 
1370   using InfoSectionMap = MapVector<object::SectionRef, DWARFSectionMap,
1371                                    std::map<object::SectionRef, unsigned>>;
1372 
1373   InfoSectionMap InfoSections;
1374   InfoSectionMap TypesSections;
1375   InfoSectionMap InfoDWOSections;
1376   InfoSectionMap TypesDWOSections;
1377 
1378   DWARFSectionMap LocSection;
1379   DWARFSectionMap LoclistsSection;
1380   DWARFSectionMap LineSection;
1381   DWARFSectionMap RangesSection;
1382   DWARFSectionMap RnglistsSection;
1383   DWARFSectionMap StrOffsetsSection;
1384   DWARFSectionMap LineDWOSection;
1385   DWARFSectionMap FrameSection;
1386   DWARFSectionMap EHFrameSection;
1387   DWARFSectionMap LocDWOSection;
1388   DWARFSectionMap StrOffsetsDWOSection;
1389   DWARFSectionMap RangesDWOSection;
1390   DWARFSectionMap RnglistsDWOSection;
1391   DWARFSectionMap AddrSection;
1392   DWARFSectionMap AppleNamesSection;
1393   DWARFSectionMap AppleTypesSection;
1394   DWARFSectionMap AppleNamespacesSection;
1395   DWARFSectionMap AppleObjCSection;
1396   DWARFSectionMap NamesSection;
1397   DWARFSectionMap PubnamesSection;
1398   DWARFSectionMap PubtypesSection;
1399   DWARFSectionMap GnuPubnamesSection;
1400   DWARFSectionMap GnuPubtypesSection;
1401 
1402   DWARFSectionMap *mapNameToDWARFSection(StringRef Name) {
1403     return StringSwitch<DWARFSectionMap *>(Name)
1404         .Case("debug_loc", &LocSection)
1405         .Case("debug_loclists", &LoclistsSection)
1406         .Case("debug_line", &LineSection)
1407         .Case("debug_frame", &FrameSection)
1408         .Case("eh_frame", &EHFrameSection)
1409         .Case("debug_str_offsets", &StrOffsetsSection)
1410         .Case("debug_ranges", &RangesSection)
1411         .Case("debug_rnglists", &RnglistsSection)
1412         .Case("debug_loc.dwo", &LocDWOSection)
1413         .Case("debug_line.dwo", &LineDWOSection)
1414         .Case("debug_names", &NamesSection)
1415         .Case("debug_rnglists.dwo", &RnglistsDWOSection)
1416         .Case("debug_str_offsets.dwo", &StrOffsetsDWOSection)
1417         .Case("debug_addr", &AddrSection)
1418         .Case("apple_names", &AppleNamesSection)
1419         .Case("debug_pubnames", &PubnamesSection)
1420         .Case("debug_pubtypes", &PubtypesSection)
1421         .Case("debug_gnu_pubnames", &GnuPubnamesSection)
1422         .Case("debug_gnu_pubtypes", &GnuPubtypesSection)
1423         .Case("apple_types", &AppleTypesSection)
1424         .Case("apple_namespaces", &AppleNamespacesSection)
1425         .Case("apple_namespac", &AppleNamespacesSection)
1426         .Case("apple_objc", &AppleObjCSection)
1427         .Default(nullptr);
1428   }
1429 
1430   StringRef AbbrevSection;
1431   StringRef ArangesSection;
1432   StringRef StrSection;
1433   StringRef MacinfoSection;
1434   StringRef AbbrevDWOSection;
1435   StringRef StrDWOSection;
1436   StringRef CUIndexSection;
1437   StringRef GdbIndexSection;
1438   StringRef TUIndexSection;
1439   StringRef LineStrSection;
1440 
1441   // A deque holding section data whose iterators are not invalidated when
1442   // new decompressed sections are inserted at the end.
1443   std::deque<SmallString<0>> UncompressedSections;
1444 
1445   StringRef *mapSectionToMember(StringRef Name) {
1446     if (DWARFSection *Sec = mapNameToDWARFSection(Name))
1447       return &Sec->Data;
1448     return StringSwitch<StringRef *>(Name)
1449         .Case("debug_abbrev", &AbbrevSection)
1450         .Case("debug_aranges", &ArangesSection)
1451         .Case("debug_str", &StrSection)
1452         .Case("debug_macinfo", &MacinfoSection)
1453         .Case("debug_abbrev.dwo", &AbbrevDWOSection)
1454         .Case("debug_str.dwo", &StrDWOSection)
1455         .Case("debug_cu_index", &CUIndexSection)
1456         .Case("debug_tu_index", &TUIndexSection)
1457         .Case("gdb_index", &GdbIndexSection)
1458         .Case("debug_line_str", &LineStrSection)
1459         // Any more debug info sections go here.
1460         .Default(nullptr);
1461   }
1462 
1463   /// If Sec is compressed section, decompresses and updates its contents
1464   /// provided by Data. Otherwise leaves it unchanged.
1465   Error maybeDecompress(const object::SectionRef &Sec, StringRef Name,
1466                         StringRef &Data) {
1467     if (!Decompressor::isCompressed(Sec))
1468       return Error::success();
1469 
1470     Expected<Decompressor> Decompressor =
1471         Decompressor::create(Name, Data, IsLittleEndian, AddressSize == 8);
1472     if (!Decompressor)
1473       return Decompressor.takeError();
1474 
1475     SmallString<0> Out;
1476     if (auto Err = Decompressor->resizeAndDecompress(Out))
1477       return Err;
1478 
1479     UncompressedSections.push_back(std::move(Out));
1480     Data = UncompressedSections.back();
1481 
1482     return Error::success();
1483   }
1484 
1485 public:
1486   DWARFObjInMemory(const StringMap<std::unique_ptr<MemoryBuffer>> &Sections,
1487                    uint8_t AddrSize, bool IsLittleEndian)
1488       : IsLittleEndian(IsLittleEndian) {
1489     for (const auto &SecIt : Sections) {
1490       if (StringRef *SectionData = mapSectionToMember(SecIt.first()))
1491         *SectionData = SecIt.second->getBuffer();
1492       else if (SecIt.first() == "debug_info")
1493         // Find debug_info and debug_types data by section rather than name as
1494         // there are multiple, comdat grouped, of these sections.
1495         InfoSections[SectionRef()].Data = SecIt.second->getBuffer();
1496       else if (SecIt.first() == "debug_info.dwo")
1497         InfoDWOSections[SectionRef()].Data = SecIt.second->getBuffer();
1498       else if (SecIt.first() == "debug_types")
1499         TypesSections[SectionRef()].Data = SecIt.second->getBuffer();
1500       else if (SecIt.first() == "debug_types.dwo")
1501         TypesDWOSections[SectionRef()].Data = SecIt.second->getBuffer();
1502     }
1503   }
1504   DWARFObjInMemory(const object::ObjectFile &Obj, const LoadedObjectInfo *L,
1505                    function_ref<ErrorPolicy(Error)> HandleError)
1506       : IsLittleEndian(Obj.isLittleEndian()),
1507         AddressSize(Obj.getBytesInAddress()), FileName(Obj.getFileName()),
1508         Obj(&Obj) {
1509 
1510     StringMap<unsigned> SectionAmountMap;
1511     for (const SectionRef &Section : Obj.sections()) {
1512       StringRef Name;
1513       if (auto NameOrErr = Section.getName())
1514         Name = *NameOrErr;
1515       else
1516         consumeError(NameOrErr.takeError());
1517 
1518       ++SectionAmountMap[Name];
1519       SectionNames.push_back({ Name, true });
1520 
1521       // Skip BSS and Virtual sections, they aren't interesting.
1522       if (Section.isBSS() || Section.isVirtual())
1523         continue;
1524 
1525       // Skip sections stripped by dsymutil.
1526       if (Section.isStripped())
1527         continue;
1528 
1529       StringRef Data;
1530       Expected<section_iterator> SecOrErr = Section.getRelocatedSection();
1531       if (!SecOrErr) {
1532         ErrorPolicy EP = HandleError(createError(
1533             "failed to get relocated section: ", SecOrErr.takeError()));
1534         if (EP == ErrorPolicy::Halt)
1535           return;
1536         continue;
1537       }
1538 
1539       // Try to obtain an already relocated version of this section.
1540       // Else use the unrelocated section from the object file. We'll have to
1541       // apply relocations ourselves later.
1542       section_iterator RelocatedSection = *SecOrErr;
1543       if (!L || !L->getLoadedSectionContents(*RelocatedSection, Data)) {
1544         Expected<StringRef> E = Section.getContents();
1545         if (E)
1546           Data = *E;
1547         else
1548           // maybeDecompress below will error.
1549           consumeError(E.takeError());
1550       }
1551 
1552       if (auto Err = maybeDecompress(Section, Name, Data)) {
1553         ErrorPolicy EP = HandleError(createError(
1554             "failed to decompress '" + Name + "', ", std::move(Err)));
1555         if (EP == ErrorPolicy::Halt)
1556           return;
1557         continue;
1558       }
1559 
1560       // Compressed sections names in GNU style starts from ".z",
1561       // at this point section is decompressed and we drop compression prefix.
1562       Name = Name.substr(
1563           Name.find_first_not_of("._z")); // Skip ".", "z" and "_" prefixes.
1564 
1565       // Map platform specific debug section names to DWARF standard section
1566       // names.
1567       Name = Obj.mapDebugSectionName(Name);
1568 
1569       if (StringRef *SectionData = mapSectionToMember(Name)) {
1570         *SectionData = Data;
1571         if (Name == "debug_ranges") {
1572           // FIXME: Use the other dwo range section when we emit it.
1573           RangesDWOSection.Data = Data;
1574         }
1575       } else if (Name == "debug_info") {
1576         // Find debug_info and debug_types data by section rather than name as
1577         // there are multiple, comdat grouped, of these sections.
1578         InfoSections[Section].Data = Data;
1579       } else if (Name == "debug_info.dwo") {
1580         InfoDWOSections[Section].Data = Data;
1581       } else if (Name == "debug_types") {
1582         TypesSections[Section].Data = Data;
1583       } else if (Name == "debug_types.dwo") {
1584         TypesDWOSections[Section].Data = Data;
1585       }
1586 
1587       if (RelocatedSection == Obj.section_end())
1588         continue;
1589 
1590       StringRef RelSecName;
1591       if (auto NameOrErr = RelocatedSection->getName())
1592         RelSecName = *NameOrErr;
1593       else
1594         consumeError(NameOrErr.takeError());
1595 
1596       // If the section we're relocating was relocated already by the JIT,
1597       // then we used the relocated version above, so we do not need to process
1598       // relocations for it now.
1599       StringRef RelSecData;
1600       if (L && L->getLoadedSectionContents(*RelocatedSection, RelSecData))
1601         continue;
1602 
1603       // In Mach-o files, the relocations do not need to be applied if
1604       // there is no load offset to apply. The value read at the
1605       // relocation point already factors in the section address
1606       // (actually applying the relocations will produce wrong results
1607       // as the section address will be added twice).
1608       if (!L && isa<MachOObjectFile>(&Obj))
1609         continue;
1610 
1611       RelSecName = RelSecName.substr(
1612           RelSecName.find_first_not_of("._z")); // Skip . and _ prefixes.
1613 
1614       // TODO: Add support for relocations in other sections as needed.
1615       // Record relocations for the debug_info and debug_line sections.
1616       DWARFSectionMap *Sec = mapNameToDWARFSection(RelSecName);
1617       RelocAddrMap *Map = Sec ? &Sec->Relocs : nullptr;
1618       if (!Map) {
1619         // Find debug_info and debug_types relocs by section rather than name
1620         // as there are multiple, comdat grouped, of these sections.
1621         if (RelSecName == "debug_info")
1622           Map = &static_cast<DWARFSectionMap &>(InfoSections[*RelocatedSection])
1623                      .Relocs;
1624         else if (RelSecName == "debug_info.dwo")
1625           Map = &static_cast<DWARFSectionMap &>(
1626                      InfoDWOSections[*RelocatedSection])
1627                      .Relocs;
1628         else if (RelSecName == "debug_types")
1629           Map =
1630               &static_cast<DWARFSectionMap &>(TypesSections[*RelocatedSection])
1631                    .Relocs;
1632         else if (RelSecName == "debug_types.dwo")
1633           Map = &static_cast<DWARFSectionMap &>(
1634                      TypesDWOSections[*RelocatedSection])
1635                      .Relocs;
1636         else
1637           continue;
1638       }
1639 
1640       if (Section.relocation_begin() == Section.relocation_end())
1641         continue;
1642 
1643       // Symbol to [address, section index] cache mapping.
1644       std::map<SymbolRef, SymInfo> AddrCache;
1645       bool (*Supports)(uint64_t);
1646       RelocationResolver Resolver;
1647       std::tie(Supports, Resolver) = getRelocationResolver(Obj);
1648       for (const RelocationRef &Reloc : Section.relocations()) {
1649         // FIXME: it's not clear how to correctly handle scattered
1650         // relocations.
1651         if (isRelocScattered(Obj, Reloc))
1652           continue;
1653 
1654         Expected<SymInfo> SymInfoOrErr =
1655             getSymbolInfo(Obj, Reloc, L, AddrCache);
1656         if (!SymInfoOrErr) {
1657           if (HandleError(SymInfoOrErr.takeError()) == ErrorPolicy::Halt)
1658             return;
1659           continue;
1660         }
1661 
1662         // Check if Resolver can handle this relocation type early so as not to
1663         // handle invalid cases in DWARFDataExtractor.
1664         //
1665         // TODO Don't store Resolver in every RelocAddrEntry.
1666         if (Supports && Supports(Reloc.getType())) {
1667           auto I = Map->try_emplace(
1668               Reloc.getOffset(),
1669               RelocAddrEntry{SymInfoOrErr->SectionIndex, Reloc,
1670                              SymInfoOrErr->Address,
1671                              Optional<object::RelocationRef>(), 0, Resolver});
1672           // If we didn't successfully insert that's because we already had a
1673           // relocation for that offset. Store it as a second relocation in the
1674           // same RelocAddrEntry instead.
1675           if (!I.second) {
1676             RelocAddrEntry &entry = I.first->getSecond();
1677             if (entry.Reloc2) {
1678               ErrorPolicy EP = HandleError(createError(
1679                   "At most two relocations per offset are supported"));
1680               if (EP == ErrorPolicy::Halt)
1681                 return;
1682             }
1683             entry.Reloc2 = Reloc;
1684             entry.SymbolValue2 = SymInfoOrErr->Address;
1685           }
1686         } else {
1687           SmallString<32> Type;
1688           Reloc.getTypeName(Type);
1689           ErrorPolicy EP = HandleError(
1690               createError("failed to compute relocation: " + Type + ", ",
1691                           errorCodeToError(object_error::parse_failed)));
1692           if (EP == ErrorPolicy::Halt)
1693             return;
1694         }
1695       }
1696     }
1697 
1698     for (SectionName &S : SectionNames)
1699       if (SectionAmountMap[S.Name] > 1)
1700         S.IsNameUnique = false;
1701   }
1702 
1703   Optional<RelocAddrEntry> find(const DWARFSection &S,
1704                                 uint64_t Pos) const override {
1705     auto &Sec = static_cast<const DWARFSectionMap &>(S);
1706     RelocAddrMap::const_iterator AI = Sec.Relocs.find(Pos);
1707     if (AI == Sec.Relocs.end())
1708       return None;
1709     return AI->second;
1710   }
1711 
1712   const object::ObjectFile *getFile() const override { return Obj; }
1713 
1714   ArrayRef<SectionName> getSectionNames() const override {
1715     return SectionNames;
1716   }
1717 
1718   bool isLittleEndian() const override { return IsLittleEndian; }
1719   StringRef getAbbrevDWOSection() const override { return AbbrevDWOSection; }
1720   const DWARFSection &getLineDWOSection() const override {
1721     return LineDWOSection;
1722   }
1723   const DWARFSection &getLocDWOSection() const override {
1724     return LocDWOSection;
1725   }
1726   StringRef getStrDWOSection() const override { return StrDWOSection; }
1727   const DWARFSection &getStrOffsetsDWOSection() const override {
1728     return StrOffsetsDWOSection;
1729   }
1730   const DWARFSection &getRangesDWOSection() const override {
1731     return RangesDWOSection;
1732   }
1733   const DWARFSection &getRnglistsDWOSection() const override {
1734     return RnglistsDWOSection;
1735   }
1736   const DWARFSection &getAddrSection() const override { return AddrSection; }
1737   StringRef getCUIndexSection() const override { return CUIndexSection; }
1738   StringRef getGdbIndexSection() const override { return GdbIndexSection; }
1739   StringRef getTUIndexSection() const override { return TUIndexSection; }
1740 
1741   // DWARF v5
1742   const DWARFSection &getStrOffsetsSection() const override {
1743     return StrOffsetsSection;
1744   }
1745   StringRef getLineStrSection() const override { return LineStrSection; }
1746 
1747   // Sections for DWARF5 split dwarf proposal.
1748   void forEachInfoDWOSections(
1749       function_ref<void(const DWARFSection &)> F) const override {
1750     for (auto &P : InfoDWOSections)
1751       F(P.second);
1752   }
1753   void forEachTypesDWOSections(
1754       function_ref<void(const DWARFSection &)> F) const override {
1755     for (auto &P : TypesDWOSections)
1756       F(P.second);
1757   }
1758 
1759   StringRef getAbbrevSection() const override { return AbbrevSection; }
1760   const DWARFSection &getLocSection() const override { return LocSection; }
1761   const DWARFSection &getLoclistsSection() const override { return LoclistsSection; }
1762   StringRef getArangesSection() const override { return ArangesSection; }
1763   const DWARFSection &getFrameSection() const override {
1764     return FrameSection;
1765   }
1766   const DWARFSection &getEHFrameSection() const override {
1767     return EHFrameSection;
1768   }
1769   const DWARFSection &getLineSection() const override { return LineSection; }
1770   StringRef getStrSection() const override { return StrSection; }
1771   const DWARFSection &getRangesSection() const override { return RangesSection; }
1772   const DWARFSection &getRnglistsSection() const override {
1773     return RnglistsSection;
1774   }
1775   StringRef getMacinfoSection() const override { return MacinfoSection; }
1776   const DWARFSection &getPubnamesSection() const override { return PubnamesSection; }
1777   const DWARFSection &getPubtypesSection() const override { return PubtypesSection; }
1778   const DWARFSection &getGnuPubnamesSection() const override {
1779     return GnuPubnamesSection;
1780   }
1781   const DWARFSection &getGnuPubtypesSection() const override {
1782     return GnuPubtypesSection;
1783   }
1784   const DWARFSection &getAppleNamesSection() const override {
1785     return AppleNamesSection;
1786   }
1787   const DWARFSection &getAppleTypesSection() const override {
1788     return AppleTypesSection;
1789   }
1790   const DWARFSection &getAppleNamespacesSection() const override {
1791     return AppleNamespacesSection;
1792   }
1793   const DWARFSection &getAppleObjCSection() const override {
1794     return AppleObjCSection;
1795   }
1796   const DWARFSection &getNamesSection() const override {
1797     return NamesSection;
1798   }
1799 
1800   StringRef getFileName() const override { return FileName; }
1801   uint8_t getAddressSize() const override { return AddressSize; }
1802   void forEachInfoSections(
1803       function_ref<void(const DWARFSection &)> F) const override {
1804     for (auto &P : InfoSections)
1805       F(P.second);
1806   }
1807   void forEachTypesSections(
1808       function_ref<void(const DWARFSection &)> F) const override {
1809     for (auto &P : TypesSections)
1810       F(P.second);
1811   }
1812 };
1813 } // namespace
1814 
1815 std::unique_ptr<DWARFContext>
1816 DWARFContext::create(const object::ObjectFile &Obj, const LoadedObjectInfo *L,
1817                      function_ref<ErrorPolicy(Error)> HandleError,
1818                      std::string DWPName) {
1819   auto DObj = std::make_unique<DWARFObjInMemory>(Obj, L, HandleError);
1820   return std::make_unique<DWARFContext>(std::move(DObj), std::move(DWPName));
1821 }
1822 
1823 std::unique_ptr<DWARFContext>
1824 DWARFContext::create(const StringMap<std::unique_ptr<MemoryBuffer>> &Sections,
1825                      uint8_t AddrSize, bool isLittleEndian) {
1826   auto DObj =
1827       std::make_unique<DWARFObjInMemory>(Sections, AddrSize, isLittleEndian);
1828   return std::make_unique<DWARFContext>(std::move(DObj), "");
1829 }
1830 
1831 Error DWARFContext::loadRegisterInfo(const object::ObjectFile &Obj) {
1832   // Detect the architecture from the object file. We usually don't need OS
1833   // info to lookup a target and create register info.
1834   Triple TT;
1835   TT.setArch(Triple::ArchType(Obj.getArch()));
1836   TT.setVendor(Triple::UnknownVendor);
1837   TT.setOS(Triple::UnknownOS);
1838   std::string TargetLookupError;
1839   const Target *TheTarget =
1840       TargetRegistry::lookupTarget(TT.str(), TargetLookupError);
1841   if (!TargetLookupError.empty())
1842     return createStringError(errc::invalid_argument,
1843                              TargetLookupError.c_str());
1844   RegInfo.reset(TheTarget->createMCRegInfo(TT.str()));
1845   return Error::success();
1846 }
1847 
1848 uint8_t DWARFContext::getCUAddrSize() {
1849   // In theory, different compile units may have different address byte
1850   // sizes, but for simplicity we just use the address byte size of the
1851   // last compile unit. In practice the address size field is repeated across
1852   // various DWARF headers (at least in version 5) to make it easier to dump
1853   // them independently, not to enable varying the address size.
1854   uint8_t Addr = 0;
1855   for (const auto &CU : compile_units()) {
1856     Addr = CU->getAddressByteSize();
1857     break;
1858   }
1859   return Addr;
1860 }
1861 
1862 void DWARFContext::dumpWarning(Error Warning) {
1863   handleAllErrors(std::move(Warning), [](ErrorInfoBase &Info) {
1864       WithColor::warning() << Info.message() << '\n';
1865   });
1866 }
1867