llvm.org GIT mirror llvm / bfd9349 lib / DebugInfo / DWARF / DWARFContext.cpp
bfd9349

Tree @bfd9349 (Download .tar.gz)

DWARFContext.cpp @bfd9349raw · history · blame

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
//===- DWARFContext.cpp ---------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "llvm/DebugInfo/DWARF/DWARFContext.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/BinaryFormat/Dwarf.h"
#include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAddr.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugArangeSet.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugPubTable.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugRangeList.h"
#include "llvm/DebugInfo/DWARF/DWARFDebugRnglists.h"
#include "llvm/DebugInfo/DWARF/DWARFDie.h"
#include "llvm/DebugInfo/DWARF/DWARFFormValue.h"
#include "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
#include "llvm/DebugInfo/DWARF/DWARFSection.h"
#include "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"
#include "llvm/DebugInfo/DWARF/DWARFVerifier.h"
#include "llvm/MC/MCRegisterInfo.h"
#include "llvm/Object/Decompressor.h"
#include "llvm/Object/MachO.h"
#include "llvm/Object/ObjectFile.h"
#include "llvm/Object/RelocationResolver.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/DataExtractor.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/Format.h"
#include "llvm/Support/LEB128.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Path.h"
#include "llvm/Support/TargetRegistry.h"
#include "llvm/Support/WithColor.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cstdint>
#include <deque>
#include <map>
#include <string>
#include <utility>
#include <vector>

using namespace llvm;
using namespace dwarf;
using namespace object;

#define DEBUG_TYPE "dwarf"

using DWARFLineTable = DWARFDebugLine::LineTable;
using FileLineInfoKind = DILineInfoSpecifier::FileLineInfoKind;
using FunctionNameKind = DILineInfoSpecifier::FunctionNameKind;

DWARFContext::DWARFContext(std::unique_ptr<const DWARFObject> DObj,
                           std::string DWPName)
    : DIContext(CK_DWARF), DWPName(std::move(DWPName)), DObj(std::move(DObj)) {}

DWARFContext::~DWARFContext() = default;

/// Dump the UUID load command.
static void dumpUUID(raw_ostream &OS, const ObjectFile &Obj) {
  auto *MachO = dyn_cast<MachOObjectFile>(&Obj);
  if (!MachO)
    return;
  for (auto LC : MachO->load_commands()) {
    raw_ostream::uuid_t UUID;
    if (LC.C.cmd == MachO::LC_UUID) {
      if (LC.C.cmdsize < sizeof(UUID) + sizeof(LC.C)) {
        OS << "error: UUID load command is too short.\n";
        return;
      }
      OS << "UUID: ";
      memcpy(&UUID, LC.Ptr+sizeof(LC.C), sizeof(UUID));
      OS.write_uuid(UUID);
      Triple T = MachO->getArchTriple();
      OS << " (" << T.getArchName() << ')';
      OS << ' ' << MachO->getFileName() << '\n';
    }
  }
}

using ContributionCollection =
    std::vector<Optional<StrOffsetsContributionDescriptor>>;

// Collect all the contributions to the string offsets table from all units,
// sort them by their starting offsets and remove duplicates.
static ContributionCollection
collectContributionData(DWARFContext::unit_iterator_range Units) {
  ContributionCollection Contributions;
  for (const auto &U : Units)
    if (const auto &C = U->getStringOffsetsTableContribution())
      Contributions.push_back(C);
  // Sort the contributions so that any invalid ones are placed at
  // the start of the contributions vector. This way they are reported
  // first.
  llvm::sort(Contributions,
             [](const Optional<StrOffsetsContributionDescriptor> &L,
                const Optional<StrOffsetsContributionDescriptor> &R) {
               if (L && R)
                 return L->Base < R->Base;
               return R.hasValue();
             });

  // Uniquify contributions, as it is possible that units (specifically
  // type units in dwo or dwp files) share contributions. We don't want
  // to report them more than once.
  Contributions.erase(
      std::unique(Contributions.begin(), Contributions.end(),
                  [](const Optional<StrOffsetsContributionDescriptor> &L,
                     const Optional<StrOffsetsContributionDescriptor> &R) {
                    if (L && R)
                      return L->Base == R->Base && L->Size == R->Size;
                    return false;
                  }),
      Contributions.end());
  return Contributions;
}

static void dumpDWARFv5StringOffsetsSection(
    raw_ostream &OS, StringRef SectionName, const DWARFObject &Obj,
    const DWARFSection &StringOffsetsSection, StringRef StringSection,
    DWARFContext::unit_iterator_range Units, bool LittleEndian) {
  auto Contributions = collectContributionData(Units);
  DWARFDataExtractor StrOffsetExt(Obj, StringOffsetsSection, LittleEndian, 0);
  DataExtractor StrData(StringSection, LittleEndian, 0);
  uint64_t SectionSize = StringOffsetsSection.Data.size();
  uint32_t Offset = 0;
  for (auto &Contribution : Contributions) {
    // Report an ill-formed contribution.
    if (!Contribution) {
      OS << "error: invalid contribution to string offsets table in section ."
         << SectionName << ".\n";
      return;
    }

    dwarf::DwarfFormat Format = Contribution->getFormat();
    uint16_t Version = Contribution->getVersion();
    uint64_t ContributionHeader = Contribution->Base;
    // In DWARF v5 there is a contribution header that immediately precedes
    // the string offsets base (the location we have previously retrieved from
    // the CU DIE's DW_AT_str_offsets attribute). The header is located either
    // 8 or 16 bytes before the base, depending on the contribution's format.
    if (Version >= 5)
      ContributionHeader -= Format == DWARF32 ? 8 : 16;

    // Detect overlapping contributions.
    if (Offset > ContributionHeader) {
      WithColor::error()
          << "overlapping contributions to string offsets table in section ."
          << SectionName << ".\n";
      return;
    }
    // Report a gap in the table.
    if (Offset < ContributionHeader) {
      OS << format("0x%8.8x: Gap, length = ", Offset);
      OS << (ContributionHeader - Offset) << "\n";
    }
    OS << format("0x%8.8x: ", (uint32_t)ContributionHeader);
    // In DWARF v5 the contribution size in the descriptor does not equal
    // the originally encoded length (it does not contain the length of the
    // version field and the padding, a total of 4 bytes). Add them back in
    // for reporting.
    OS << "Contribution size = " << (Contribution->Size + (Version < 5 ? 0 : 4))
       << ", Format = " << (Format == DWARF32 ? "DWARF32" : "DWARF64")
       << ", Version = " << Version << "\n";

    Offset = Contribution->Base;
    unsigned EntrySize = Contribution->getDwarfOffsetByteSize();
    while (Offset - Contribution->Base < Contribution->Size) {
      OS << format("0x%8.8x: ", Offset);
      // FIXME: We can only extract strings if the offset fits in 32 bits.
      uint64_t StringOffset =
          StrOffsetExt.getRelocatedValue(EntrySize, &Offset);
      // Extract the string if we can and display it. Otherwise just report
      // the offset.
      if (StringOffset <= std::numeric_limits<uint32_t>::max()) {
        uint32_t StringOffset32 = (uint32_t)StringOffset;
        OS << format("%8.8x ", StringOffset32);
        const char *S = StrData.getCStr(&StringOffset32);
        if (S)
          OS << format("\"%s\"", S);
      } else
        OS << format("%16.16" PRIx64 " ", StringOffset);
      OS << "\n";
    }
  }
  // Report a gap at the end of the table.
  if (Offset < SectionSize) {
    OS << format("0x%8.8x: Gap, length = ", Offset);
    OS << (SectionSize - Offset) << "\n";
  }
}

// Dump a DWARF string offsets section. This may be a DWARF v5 formatted
// string offsets section, where each compile or type unit contributes a
// number of entries (string offsets), with each contribution preceded by
// a header containing size and version number. Alternatively, it may be a
// monolithic series of string offsets, as generated by the pre-DWARF v5
// implementation of split DWARF.
static void dumpStringOffsetsSection(raw_ostream &OS, StringRef SectionName,
                                     const DWARFObject &Obj,
                                     const DWARFSection &StringOffsetsSection,
                                     StringRef StringSection,
                                     DWARFContext::unit_iterator_range Units,
                                     bool LittleEndian, unsigned MaxVersion) {
  // If we have at least one (compile or type) unit with DWARF v5 or greater,
  // we assume that the section is formatted like a DWARF v5 string offsets
  // section.
  if (MaxVersion >= 5)
    dumpDWARFv5StringOffsetsSection(OS, SectionName, Obj, StringOffsetsSection,
                                    StringSection, Units, LittleEndian);
  else {
    DataExtractor strOffsetExt(StringOffsetsSection.Data, LittleEndian, 0);
    uint32_t offset = 0;
    uint64_t size = StringOffsetsSection.Data.size();
    // Ensure that size is a multiple of the size of an entry.
    if (size & ((uint64_t)(sizeof(uint32_t) - 1))) {
      OS << "error: size of ." << SectionName << " is not a multiple of "
         << sizeof(uint32_t) << ".\n";
      size &= -(uint64_t)sizeof(uint32_t);
    }
    DataExtractor StrData(StringSection, LittleEndian, 0);
    while (offset < size) {
      OS << format("0x%8.8x: ", offset);
      uint32_t StringOffset = strOffsetExt.getU32(&offset);
      OS << format("%8.8x  ", StringOffset);
      const char *S = StrData.getCStr(&StringOffset);
      if (S)
        OS << format("\"%s\"", S);
      OS << "\n";
    }
  }
}

// Dump the .debug_addr section.
static void dumpAddrSection(raw_ostream &OS, DWARFDataExtractor &AddrData,
                            DIDumpOptions DumpOpts, uint16_t Version,
                            uint8_t AddrSize) {
  uint32_t Offset = 0;
  while (AddrData.isValidOffset(Offset)) {
    DWARFDebugAddrTable AddrTable;
    uint32_t TableOffset = Offset;
    if (Error Err = AddrTable.extract(AddrData, &Offset, Version, AddrSize,
                                      DWARFContext::dumpWarning)) {
      WithColor::error() << toString(std::move(Err)) << '\n';
      // Keep going after an error, if we can, assuming that the length field
      // could be read. If it couldn't, stop reading the section.
      if (!AddrTable.hasValidLength())
        break;
      uint64_t Length = AddrTable.getLength();
      Offset = TableOffset + Length;
    } else {
      AddrTable.dump(OS, DumpOpts);
    }
  }
}

// Dump the .debug_rnglists or .debug_rnglists.dwo section (DWARF v5).
static void dumpRnglistsSection(
    raw_ostream &OS, DWARFDataExtractor &rnglistData,
    llvm::function_ref<Optional<object::SectionedAddress>(uint32_t)>
        LookupPooledAddress,
    DIDumpOptions DumpOpts) {
  uint32_t Offset = 0;
  while (rnglistData.isValidOffset(Offset)) {
    llvm::DWARFDebugRnglistTable Rnglists;
    uint32_t TableOffset = Offset;
    if (Error Err = Rnglists.extract(rnglistData, &Offset)) {
      WithColor::error() << toString(std::move(Err)) << '\n';
      uint64_t Length = Rnglists.length();
      // Keep going after an error, if we can, assuming that the length field
      // could be read. If it couldn't, stop reading the section.
      if (Length == 0)
        break;
      Offset = TableOffset + Length;
    } else {
      Rnglists.dump(OS, LookupPooledAddress, DumpOpts);
    }
  }
}

static void dumpLoclistsSection(raw_ostream &OS, DIDumpOptions DumpOpts,
                                DWARFDataExtractor Data,
                                const MCRegisterInfo *MRI,
                                Optional<uint64_t> DumpOffset) {
  uint32_t Offset = 0;
  DWARFDebugLoclists Loclists;

  DWARFListTableHeader Header(".debug_loclists", "locations");
  if (Error E = Header.extract(Data, &Offset)) {
    WithColor::error() << toString(std::move(E)) << '\n';
    return;
  }

  Header.dump(OS, DumpOpts);
  DataExtractor LocData(Data.getData().drop_front(Offset),
                        Data.isLittleEndian(), Header.getAddrSize());

  Loclists.parse(LocData, Header.getVersion());
  Loclists.dump(OS, 0, MRI, DumpOffset);
}

void DWARFContext::dump(
    raw_ostream &OS, DIDumpOptions DumpOpts,
    std::array<Optional<uint64_t>, DIDT_ID_Count> DumpOffsets) {

  uint64_t DumpType = DumpOpts.DumpType;

  StringRef Extension = sys::path::extension(DObj->getFileName());
  bool IsDWO = (Extension == ".dwo") || (Extension == ".dwp");

  // Print UUID header.
  const auto *ObjFile = DObj->getFile();
  if (DumpType & DIDT_UUID)
    dumpUUID(OS, *ObjFile);

  // Print a header for each explicitly-requested section.
  // Otherwise just print one for non-empty sections.
  // Only print empty .dwo section headers when dumping a .dwo file.
  bool Explicit = DumpType != DIDT_All && !IsDWO;
  bool ExplicitDWO = Explicit && IsDWO;
  auto shouldDump = [&](bool Explicit, const char *Name, unsigned ID,
                        StringRef Section) -> Optional<uint64_t> * {
    unsigned Mask = 1U << ID;
    bool Should = (DumpType & Mask) && (Explicit || !Section.empty());
    if (!Should)
      return nullptr;
    OS << "\n" << Name << " contents:\n";
    return &DumpOffsets[ID];
  };

  // Dump individual sections.
  if (shouldDump(Explicit, ".debug_abbrev", DIDT_ID_DebugAbbrev,
                 DObj->getAbbrevSection()))
    getDebugAbbrev()->dump(OS);
  if (shouldDump(ExplicitDWO, ".debug_abbrev.dwo", DIDT_ID_DebugAbbrev,
                 DObj->getAbbrevDWOSection()))
    getDebugAbbrevDWO()->dump(OS);

  auto dumpDebugInfo = [&](const char *Name, unit_iterator_range Units) {
    OS << '\n' << Name << " contents:\n";
    if (auto DumpOffset = DumpOffsets[DIDT_ID_DebugInfo])
      for (const auto &U : Units)
        U->getDIEForOffset(DumpOffset.getValue())
            .dump(OS, 0, DumpOpts.noImplicitRecursion());
    else
      for (const auto &U : Units)
        U->dump(OS, DumpOpts);
  };
  if ((DumpType & DIDT_DebugInfo)) {
    if (Explicit || getNumCompileUnits())
      dumpDebugInfo(".debug_info", info_section_units());
    if (ExplicitDWO || getNumDWOCompileUnits())
      dumpDebugInfo(".debug_info.dwo", dwo_info_section_units());
  }

  auto dumpDebugType = [&](const char *Name, unit_iterator_range Units) {
    OS << '\n' << Name << " contents:\n";
    for (const auto &U : Units)
      if (auto DumpOffset = DumpOffsets[DIDT_ID_DebugTypes])
        U->getDIEForOffset(*DumpOffset)
            .dump(OS, 0, DumpOpts.noImplicitRecursion());
      else
        U->dump(OS, DumpOpts);
  };
  if ((DumpType & DIDT_DebugTypes)) {
    if (Explicit || getNumTypeUnits())
      dumpDebugType(".debug_types", types_section_units());
    if (ExplicitDWO || getNumDWOTypeUnits())
      dumpDebugType(".debug_types.dwo", dwo_types_section_units());
  }

  if (const auto *Off = shouldDump(Explicit, ".debug_loc", DIDT_ID_DebugLoc,
                                   DObj->getLocSection().Data)) {
    getDebugLoc()->dump(OS, getRegisterInfo(), *Off);
  }
  if (const auto *Off =
          shouldDump(Explicit, ".debug_loclists", DIDT_ID_DebugLoclists,
                     DObj->getLoclistsSection().Data)) {
    DWARFDataExtractor Data(*DObj, DObj->getLoclistsSection(), isLittleEndian(),
                            0);
    dumpLoclistsSection(OS, DumpOpts, Data, getRegisterInfo(), *Off);
  }
  if (const auto *Off =
          shouldDump(ExplicitDWO, ".debug_loc.dwo", DIDT_ID_DebugLoc,
                     DObj->getLocDWOSection().Data)) {
    getDebugLocDWO()->dump(OS, 0, getRegisterInfo(), *Off);
  }

  if (const auto *Off = shouldDump(Explicit, ".debug_frame", DIDT_ID_DebugFrame,
                                   DObj->getDebugFrameSection()))
    getDebugFrame()->dump(OS, getRegisterInfo(), *Off);

  if (const auto *Off = shouldDump(Explicit, ".eh_frame", DIDT_ID_DebugFrame,
                                   DObj->getEHFrameSection()))
    getEHFrame()->dump(OS, getRegisterInfo(), *Off);

  if (DumpType & DIDT_DebugMacro) {
    if (Explicit || !getDebugMacro()->empty()) {
      OS << "\n.debug_macinfo contents:\n";
      getDebugMacro()->dump(OS);
    }
  }

  if (shouldDump(Explicit, ".debug_aranges", DIDT_ID_DebugAranges,
                 DObj->getARangeSection())) {
    uint32_t offset = 0;
    DataExtractor arangesData(DObj->getARangeSection(), isLittleEndian(), 0);
    DWARFDebugArangeSet set;
    while (set.extract(arangesData, &offset))
      set.dump(OS);
  }

  auto DumpLineSection = [&](DWARFDebugLine::SectionParser Parser,
                             DIDumpOptions DumpOpts,
                             Optional<uint64_t> DumpOffset) {
    while (!Parser.done()) {
      if (DumpOffset && Parser.getOffset() != *DumpOffset) {
        Parser.skip(dumpWarning);
        continue;
      }
      OS << "debug_line[" << format("0x%8.8x", Parser.getOffset()) << "]\n";
      if (DumpOpts.Verbose) {
        Parser.parseNext(dumpWarning, dumpWarning, &OS);
      } else {
        DWARFDebugLine::LineTable LineTable =
            Parser.parseNext(dumpWarning, dumpWarning);
        LineTable.dump(OS, DumpOpts);
      }
    }
  };

  if (const auto *Off = shouldDump(Explicit, ".debug_line", DIDT_ID_DebugLine,
                                   DObj->getLineSection().Data)) {
    DWARFDataExtractor LineData(*DObj, DObj->getLineSection(), isLittleEndian(),
                                0);
    DWARFDebugLine::SectionParser Parser(LineData, *this, compile_units(),
                                         type_units());
    DumpLineSection(Parser, DumpOpts, *Off);
  }

  if (const auto *Off =
          shouldDump(ExplicitDWO, ".debug_line.dwo", DIDT_ID_DebugLine,
                     DObj->getLineDWOSection().Data)) {
    DWARFDataExtractor LineData(*DObj, DObj->getLineDWOSection(),
                                isLittleEndian(), 0);
    DWARFDebugLine::SectionParser Parser(LineData, *this, dwo_compile_units(),
                                         dwo_type_units());
    DumpLineSection(Parser, DumpOpts, *Off);
  }

  if (shouldDump(Explicit, ".debug_cu_index", DIDT_ID_DebugCUIndex,
                 DObj->getCUIndexSection())) {
    getCUIndex().dump(OS);
  }

  if (shouldDump(Explicit, ".debug_tu_index", DIDT_ID_DebugTUIndex,
                 DObj->getTUIndexSection())) {
    getTUIndex().dump(OS);
  }

  if (shouldDump(Explicit, ".debug_str", DIDT_ID_DebugStr,
                 DObj->getStringSection())) {
    DataExtractor strData(DObj->getStringSection(), isLittleEndian(), 0);
    uint32_t offset = 0;
    uint32_t strOffset = 0;
    while (const char *s = strData.getCStr(&offset)) {
      OS << format("0x%8.8x: \"%s\"\n", strOffset, s);
      strOffset = offset;
    }
  }
  if (shouldDump(ExplicitDWO, ".debug_str.dwo", DIDT_ID_DebugStr,
                 DObj->getStringDWOSection())) {
    DataExtractor strDWOData(DObj->getStringDWOSection(), isLittleEndian(), 0);
    uint32_t offset = 0;
    uint32_t strDWOOffset = 0;
    while (const char *s = strDWOData.getCStr(&offset)) {
      OS << format("0x%8.8x: \"%s\"\n", strDWOOffset, s);
      strDWOOffset = offset;
    }
  }
  if (shouldDump(Explicit, ".debug_line_str", DIDT_ID_DebugLineStr,
                 DObj->getLineStringSection())) {
    DataExtractor strData(DObj->getLineStringSection(), isLittleEndian(), 0);
    uint32_t offset = 0;
    uint32_t strOffset = 0;
    while (const char *s = strData.getCStr(&offset)) {
      OS << format("0x%8.8x: \"", strOffset);
      OS.write_escaped(s);
      OS << "\"\n";
      strOffset = offset;
    }
  }

  if (shouldDump(Explicit, ".debug_addr", DIDT_ID_DebugAddr,
                 DObj->getAddrSection().Data)) {
    DWARFDataExtractor AddrData(*DObj, DObj->getAddrSection(),
                                   isLittleEndian(), 0);
    dumpAddrSection(OS, AddrData, DumpOpts, getMaxVersion(), getCUAddrSize());
  }

  if (shouldDump(Explicit, ".debug_ranges", DIDT_ID_DebugRanges,
                 DObj->getRangeSection().Data)) {
    uint8_t savedAddressByteSize = getCUAddrSize();
    DWARFDataExtractor rangesData(*DObj, DObj->getRangeSection(),
                                  isLittleEndian(), savedAddressByteSize);
    uint32_t offset = 0;
    DWARFDebugRangeList rangeList;
    while (rangesData.isValidOffset(offset)) {
      if (Error E = rangeList.extract(rangesData, &offset)) {
        WithColor::error() << toString(std::move(E)) << '\n';
        break;
      }
      rangeList.dump(OS);
    }
  }

  auto LookupPooledAddress = [&](uint32_t Index) -> Optional<SectionedAddress> {
    const auto &CUs = compile_units();
    auto I = CUs.begin();
    if (I == CUs.end())
      return None;
    return (*I)->getAddrOffsetSectionItem(Index);
  };

  if (shouldDump(Explicit, ".debug_rnglists", DIDT_ID_DebugRnglists,
                 DObj->getRnglistsSection().Data)) {
    DWARFDataExtractor RnglistData(*DObj, DObj->getRnglistsSection(),
                                   isLittleEndian(), 0);
    dumpRnglistsSection(OS, RnglistData, LookupPooledAddress, DumpOpts);
  }

  if (shouldDump(ExplicitDWO, ".debug_rnglists.dwo", DIDT_ID_DebugRnglists,
                 DObj->getRnglistsDWOSection().Data)) {
    DWARFDataExtractor RnglistData(*DObj, DObj->getRnglistsDWOSection(),
                                   isLittleEndian(), 0);
    dumpRnglistsSection(OS, RnglistData, LookupPooledAddress, DumpOpts);
  }

  if (shouldDump(Explicit, ".debug_pubnames", DIDT_ID_DebugPubnames,
                 DObj->getPubNamesSection().Data))
    DWARFDebugPubTable(*DObj, DObj->getPubNamesSection(), isLittleEndian(), false)
        .dump(OS);

  if (shouldDump(Explicit, ".debug_pubtypes", DIDT_ID_DebugPubtypes,
                 DObj->getPubTypesSection().Data))
    DWARFDebugPubTable(*DObj, DObj->getPubTypesSection(), isLittleEndian(), false)
        .dump(OS);

  if (shouldDump(Explicit, ".debug_gnu_pubnames", DIDT_ID_DebugGnuPubnames,
                 DObj->getGnuPubNamesSection().Data))
    DWARFDebugPubTable(*DObj, DObj->getGnuPubNamesSection(), isLittleEndian(),
                       true /* GnuStyle */)
        .dump(OS);

  if (shouldDump(Explicit, ".debug_gnu_pubtypes", DIDT_ID_DebugGnuPubtypes,
                 DObj->getGnuPubTypesSection().Data))
    DWARFDebugPubTable(*DObj, DObj->getGnuPubTypesSection(), isLittleEndian(),
                       true /* GnuStyle */)
        .dump(OS);

  if (shouldDump(Explicit, ".debug_str_offsets", DIDT_ID_DebugStrOffsets,
                 DObj->getStringOffsetSection().Data))
    dumpStringOffsetsSection(OS, "debug_str_offsets", *DObj,
                             DObj->getStringOffsetSection(),
                             DObj->getStringSection(), normal_units(),
                             isLittleEndian(), getMaxVersion());
  if (shouldDump(ExplicitDWO, ".debug_str_offsets.dwo", DIDT_ID_DebugStrOffsets,
                 DObj->getStringOffsetDWOSection().Data))
    dumpStringOffsetsSection(OS, "debug_str_offsets.dwo", *DObj,
                             DObj->getStringOffsetDWOSection(),
                             DObj->getStringDWOSection(), dwo_units(),
                             isLittleEndian(), getMaxDWOVersion());

  if (shouldDump(Explicit, ".gdb_index", DIDT_ID_GdbIndex,
                 DObj->getGdbIndexSection())) {
    getGdbIndex().dump(OS);
  }

  if (shouldDump(Explicit, ".apple_names", DIDT_ID_AppleNames,
                 DObj->getAppleNamesSection().Data))
    getAppleNames().dump(OS);

  if (shouldDump(Explicit, ".apple_types", DIDT_ID_AppleTypes,
                 DObj->getAppleTypesSection().Data))
    getAppleTypes().dump(OS);

  if (shouldDump(Explicit, ".apple_namespaces", DIDT_ID_AppleNamespaces,
                 DObj->getAppleNamespacesSection().Data))
    getAppleNamespaces().dump(OS);

  if (shouldDump(Explicit, ".apple_objc", DIDT_ID_AppleObjC,
                 DObj->getAppleObjCSection().Data))
    getAppleObjC().dump(OS);
  if (shouldDump(Explicit, ".debug_names", DIDT_ID_DebugNames,
                 DObj->getDebugNamesSection().Data))
    getDebugNames().dump(OS);
}

DWARFCompileUnit *DWARFContext::getDWOCompileUnitForHash(uint64_t Hash) {
  parseDWOUnits(LazyParse);

  if (const auto &CUI = getCUIndex()) {
    if (const auto *R = CUI.getFromHash(Hash))
      return dyn_cast_or_null<DWARFCompileUnit>(
          DWOUnits.getUnitForIndexEntry(*R));
    return nullptr;
  }

  // If there's no index, just search through the CUs in the DWO - there's
  // probably only one unless this is something like LTO - though an in-process
  // built/cached lookup table could be used in that case to improve repeated
  // lookups of different CUs in the DWO.
  for (const auto &DWOCU : dwo_compile_units()) {
    // Might not have parsed DWO ID yet.
    if (!DWOCU->getDWOId()) {
      if (Optional<uint64_t> DWOId =
          toUnsigned(DWOCU->getUnitDIE().find(DW_AT_GNU_dwo_id)))
        DWOCU->setDWOId(*DWOId);
      else
        // No DWO ID?
        continue;
    }
    if (DWOCU->getDWOId() == Hash)
      return dyn_cast<DWARFCompileUnit>(DWOCU.get());
  }
  return nullptr;
}

DWARFDie DWARFContext::getDIEForOffset(uint32_t Offset) {
  parseNormalUnits();
  if (auto *CU = NormalUnits.getUnitForOffset(Offset))
    return CU->getDIEForOffset(Offset);
  return DWARFDie();
}

bool DWARFContext::verify(raw_ostream &OS, DIDumpOptions DumpOpts) {
  bool Success = true;
  DWARFVerifier verifier(OS, *this, DumpOpts);

  Success &= verifier.handleDebugAbbrev();
  if (DumpOpts.DumpType & DIDT_DebugInfo)
    Success &= verifier.handleDebugInfo();
  if (DumpOpts.DumpType & DIDT_DebugLine)
    Success &= verifier.handleDebugLine();
  Success &= verifier.handleAccelTables();
  return Success;
}

const DWARFUnitIndex &DWARFContext::getCUIndex() {
  if (CUIndex)
    return *CUIndex;

  DataExtractor CUIndexData(DObj->getCUIndexSection(), isLittleEndian(), 0);

  CUIndex = llvm::make_unique<DWARFUnitIndex>(DW_SECT_INFO);
  CUIndex->parse(CUIndexData);
  return *CUIndex;
}

const DWARFUnitIndex &DWARFContext::getTUIndex() {
  if (TUIndex)
    return *TUIndex;

  DataExtractor TUIndexData(DObj->getTUIndexSection(), isLittleEndian(), 0);

  TUIndex = llvm::make_unique<DWARFUnitIndex>(DW_SECT_TYPES);
  TUIndex->parse(TUIndexData);
  return *TUIndex;
}

DWARFGdbIndex &DWARFContext::getGdbIndex() {
  if (GdbIndex)
    return *GdbIndex;

  DataExtractor GdbIndexData(DObj->getGdbIndexSection(), true /*LE*/, 0);
  GdbIndex = llvm::make_unique<DWARFGdbIndex>();
  GdbIndex->parse(GdbIndexData);
  return *GdbIndex;
}

const DWARFDebugAbbrev *DWARFContext::getDebugAbbrev() {
  if (Abbrev)
    return Abbrev.get();

  DataExtractor abbrData(DObj->getAbbrevSection(), isLittleEndian(), 0);

  Abbrev.reset(new DWARFDebugAbbrev());
  Abbrev->extract(abbrData);
  return Abbrev.get();
}

const DWARFDebugAbbrev *DWARFContext::getDebugAbbrevDWO() {
  if (AbbrevDWO)
    return AbbrevDWO.get();

  DataExtractor abbrData(DObj->getAbbrevDWOSection(), isLittleEndian(), 0);
  AbbrevDWO.reset(new DWARFDebugAbbrev());
  AbbrevDWO->extract(abbrData);
  return AbbrevDWO.get();
}

const DWARFDebugLoc *DWARFContext::getDebugLoc() {
  if (Loc)
    return Loc.get();

  Loc.reset(new DWARFDebugLoc);
  // Assume all units have the same address byte size.
  if (getNumCompileUnits()) {
    DWARFDataExtractor LocData(*DObj, DObj->getLocSection(), isLittleEndian(),
                               getUnitAtIndex(0)->getAddressByteSize());
    Loc->parse(LocData);
  }
  return Loc.get();
}

const DWARFDebugLoclists *DWARFContext::getDebugLocDWO() {
  if (LocDWO)
    return LocDWO.get();

  LocDWO.reset(new DWARFDebugLoclists());
  // Assume all compile units have the same address byte size.
  // FIXME: We don't need AddressSize for split DWARF since relocatable
  // addresses cannot appear there. At the moment DWARFExpression requires it.
  DataExtractor LocData(DObj->getLocDWOSection().Data, isLittleEndian(), 4);
  // Use version 4. DWO does not support the DWARF v5 .debug_loclists yet and
  // that means we are parsing the new style .debug_loc (pre-standatized version
  // of the .debug_loclists).
  LocDWO->parse(LocData, 4 /* Version */);
  return LocDWO.get();
}

const DWARFDebugAranges *DWARFContext::getDebugAranges() {
  if (Aranges)
    return Aranges.get();

  Aranges.reset(new DWARFDebugAranges());
  Aranges->generate(this);
  return Aranges.get();
}

const DWARFDebugFrame *DWARFContext::getDebugFrame() {
  if (DebugFrame)
    return DebugFrame.get();

  // There's a "bug" in the DWARFv3 standard with respect to the target address
  // size within debug frame sections. While DWARF is supposed to be independent
  // of its container, FDEs have fields with size being "target address size",
  // which isn't specified in DWARF in general. It's only specified for CUs, but
  // .eh_frame can appear without a .debug_info section. Follow the example of
  // other tools (libdwarf) and extract this from the container (ObjectFile
  // provides this information). This problem is fixed in DWARFv4
  // See this dwarf-discuss discussion for more details:
  // http://lists.dwarfstd.org/htdig.cgi/dwarf-discuss-dwarfstd.org/2011-December/001173.html
  DWARFDataExtractor debugFrameData(DObj->getDebugFrameSection(),
                                    isLittleEndian(), DObj->getAddressSize());
  DebugFrame.reset(new DWARFDebugFrame(getArch(), false /* IsEH */));
  DebugFrame->parse(debugFrameData);
  return DebugFrame.get();
}

const DWARFDebugFrame *DWARFContext::getEHFrame() {
  if (EHFrame)
    return EHFrame.get();

  DWARFDataExtractor debugFrameData(DObj->getEHFrameSection(), isLittleEndian(),
                                    DObj->getAddressSize());
  DebugFrame.reset(new DWARFDebugFrame(getArch(), true /* IsEH */));
  DebugFrame->parse(debugFrameData);
  return DebugFrame.get();
}

const DWARFDebugMacro *DWARFContext::getDebugMacro() {
  if (Macro)
    return Macro.get();

  DataExtractor MacinfoData(DObj->getMacinfoSection(), isLittleEndian(), 0);
  Macro.reset(new DWARFDebugMacro());
  Macro->parse(MacinfoData);
  return Macro.get();
}

template <typename T>
static T &getAccelTable(std::unique_ptr<T> &Cache, const DWARFObject &Obj,
                        const DWARFSection &Section, StringRef StringSection,
                        bool IsLittleEndian) {
  if (Cache)
    return *Cache;
  DWARFDataExtractor AccelSection(Obj, Section, IsLittleEndian, 0);
  DataExtractor StrData(StringSection, IsLittleEndian, 0);
  Cache.reset(new T(AccelSection, StrData));
  if (Error E = Cache->extract())
    llvm::consumeError(std::move(E));
  return *Cache;
}

const DWARFDebugNames &DWARFContext::getDebugNames() {
  return getAccelTable(Names, *DObj, DObj->getDebugNamesSection(),
                       DObj->getStringSection(), isLittleEndian());
}

const AppleAcceleratorTable &DWARFContext::getAppleNames() {
  return getAccelTable(AppleNames, *DObj, DObj->getAppleNamesSection(),
                       DObj->getStringSection(), isLittleEndian());
}

const AppleAcceleratorTable &DWARFContext::getAppleTypes() {
  return getAccelTable(AppleTypes, *DObj, DObj->getAppleTypesSection(),
                       DObj->getStringSection(), isLittleEndian());
}

const AppleAcceleratorTable &DWARFContext::getAppleNamespaces() {
  return getAccelTable(AppleNamespaces, *DObj,
                       DObj->getAppleNamespacesSection(),
                       DObj->getStringSection(), isLittleEndian());
}

const AppleAcceleratorTable &DWARFContext::getAppleObjC() {
  return getAccelTable(AppleObjC, *DObj, DObj->getAppleObjCSection(),
                       DObj->getStringSection(), isLittleEndian());
}

const DWARFDebugLine::LineTable *
DWARFContext::getLineTableForUnit(DWARFUnit *U) {
  Expected<const DWARFDebugLine::LineTable *> ExpectedLineTable =
      getLineTableForUnit(U, dumpWarning);
  if (!ExpectedLineTable) {
    dumpWarning(ExpectedLineTable.takeError());
    return nullptr;
  }
  return *ExpectedLineTable;
}

Expected<const DWARFDebugLine::LineTable *> DWARFContext::getLineTableForUnit(
    DWARFUnit *U, std::function<void(Error)> RecoverableErrorCallback) {
  if (!Line)
    Line.reset(new DWARFDebugLine);

  auto UnitDIE = U->getUnitDIE();
  if (!UnitDIE)
    return nullptr;

  auto Offset = toSectionOffset(UnitDIE.find(DW_AT_stmt_list));
  if (!Offset)
    return nullptr; // No line table for this compile unit.

  uint32_t stmtOffset = *Offset + U->getLineTableOffset();
  // See if the line table is cached.
  if (const DWARFLineTable *lt = Line->getLineTable(stmtOffset))
    return lt;

  // Make sure the offset is good before we try to parse.
  if (stmtOffset >= U->getLineSection().Data.size())
    return nullptr;

  // We have to parse it first.
  DWARFDataExtractor lineData(*DObj, U->getLineSection(), isLittleEndian(),
                              U->getAddressByteSize());
  return Line->getOrParseLineTable(lineData, stmtOffset, *this, U,
                                   RecoverableErrorCallback);
}

void DWARFContext::parseNormalUnits() {
  if (!NormalUnits.empty())
    return;
  DObj->forEachInfoSections([&](const DWARFSection &S) {
    NormalUnits.addUnitsForSection(*this, S, DW_SECT_INFO);
  });
  NormalUnits.finishedInfoUnits();
  DObj->forEachTypesSections([&](const DWARFSection &S) {
    NormalUnits.addUnitsForSection(*this, S, DW_SECT_TYPES);
  });
}

void DWARFContext::parseDWOUnits(bool Lazy) {
  if (!DWOUnits.empty())
    return;
  DObj->forEachInfoDWOSections([&](const DWARFSection &S) {
    DWOUnits.addUnitsForDWOSection(*this, S, DW_SECT_INFO, Lazy);
  });
  DWOUnits.finishedInfoUnits();
  DObj->forEachTypesDWOSections([&](const DWARFSection &S) {
    DWOUnits.addUnitsForDWOSection(*this, S, DW_SECT_TYPES, Lazy);
  });
}

DWARFCompileUnit *DWARFContext::getCompileUnitForOffset(uint32_t Offset) {
  parseNormalUnits();
  return dyn_cast_or_null<DWARFCompileUnit>(
      NormalUnits.getUnitForOffset(Offset));
}

DWARFCompileUnit *DWARFContext::getCompileUnitForAddress(uint64_t Address) {
  // First, get the offset of the compile unit.
  uint32_t CUOffset = getDebugAranges()->findAddress(Address);
  // Retrieve the compile unit.
  return getCompileUnitForOffset(CUOffset);
}

DWARFContext::DIEsForAddress DWARFContext::getDIEsForAddress(uint64_t Address) {
  DIEsForAddress Result;

  DWARFCompileUnit *CU = getCompileUnitForAddress(Address);
  if (!CU)
    return Result;

  Result.CompileUnit = CU;
  Result.FunctionDIE = CU->getSubroutineForAddress(Address);

  std::vector<DWARFDie> Worklist;
  Worklist.push_back(Result.FunctionDIE);
  while (!Worklist.empty()) {
    DWARFDie DIE = Worklist.back();
    Worklist.pop_back();

    if (!DIE.isValid())
      continue;

    if (DIE.getTag() == DW_TAG_lexical_block &&
        DIE.addressRangeContainsAddress(Address)) {
      Result.BlockDIE = DIE;
      break;
    }

    for (auto Child : DIE)
      Worklist.push_back(Child);
  }

  return Result;
}

/// TODO: change input parameter from "uint64_t Address"
///       into "SectionedAddress Address"
static bool getFunctionNameAndStartLineForAddress(DWARFCompileUnit *CU,
                                                  uint64_t Address,
                                                  FunctionNameKind Kind,
                                                  std::string &FunctionName,
                                                  uint32_t &StartLine) {
  // The address may correspond to instruction in some inlined function,
  // so we have to build the chain of inlined functions and take the
  // name of the topmost function in it.
  SmallVector<DWARFDie, 4> InlinedChain;
  CU->getInlinedChainForAddress(Address, InlinedChain);
  if (InlinedChain.empty())
    return false;

  const DWARFDie &DIE = InlinedChain[0];
  bool FoundResult = false;
  const char *Name = nullptr;
  if (Kind != FunctionNameKind::None && (Name = DIE.getSubroutineName(Kind))) {
    FunctionName = Name;
    FoundResult = true;
  }
  if (auto DeclLineResult = DIE.getDeclLine()) {
    StartLine = DeclLineResult;
    FoundResult = true;
  }

  return FoundResult;
}

static Optional<uint64_t> getTypeSize(DWARFDie Type, uint64_t PointerSize) {
  if (auto SizeAttr = Type.find(DW_AT_byte_size))
    if (Optional<uint64_t> Size = SizeAttr->getAsUnsignedConstant())
      return Size;

  switch (Type.getTag()) {
  case DW_TAG_pointer_type:
  case DW_TAG_reference_type:
  case DW_TAG_rvalue_reference_type:
    return PointerSize;
  case DW_TAG_ptr_to_member_type: {
    if (DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type))
      if (BaseType.getTag() == DW_TAG_subroutine_type)
        return 2 * PointerSize;
    return PointerSize;
  }
  case DW_TAG_const_type:
  case DW_TAG_volatile_type:
  case DW_TAG_restrict_type:
  case DW_TAG_typedef: {
    if (DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type))
      return getTypeSize(BaseType, PointerSize);
    break;
  }
  case DW_TAG_array_type: {
    DWARFDie BaseType = Type.getAttributeValueAsReferencedDie(DW_AT_type);
    if (!BaseType)
      return Optional<uint64_t>();
    Optional<uint64_t> BaseSize = getTypeSize(BaseType, PointerSize);
    if (!BaseSize)
      return Optional<uint64_t>();
    uint64_t Size = *BaseSize;
    for (DWARFDie Child : Type) {
      if (Child.getTag() != DW_TAG_subrange_type)
        continue;

      if (auto ElemCountAttr = Child.find(DW_AT_count))
        if (Optional<uint64_t> ElemCount =
                ElemCountAttr->getAsUnsignedConstant())
          Size *= *ElemCount;
      if (auto UpperBoundAttr = Child.find(DW_AT_upper_bound))
        if (Optional<int64_t> UpperBound =
                UpperBoundAttr->getAsSignedConstant()) {
          int64_t LowerBound = 0;
          if (auto LowerBoundAttr = Child.find(DW_AT_lower_bound))
            LowerBound = LowerBoundAttr->getAsSignedConstant().getValueOr(0);
          Size *= *UpperBound - LowerBound + 1;
        }
    }
    return Size;
  }
  default:
    break;
  }
  return Optional<uint64_t>();
}

void DWARFContext::addLocalsForDie(DWARFCompileUnit *CU, DWARFDie Subprogram,
                                   DWARFDie Die, std::vector<DILocal> &Result) {
  if (Die.getTag() == DW_TAG_variable ||
      Die.getTag() == DW_TAG_formal_parameter) {
    DILocal Local;
    if (auto NameAttr = Subprogram.find(DW_AT_name))
      if (Optional<const char *> Name = NameAttr->getAsCString())
        Local.FunctionName = *Name;
    if (auto LocationAttr = Die.find(DW_AT_location))
      if (Optional<ArrayRef<uint8_t>> Location = LocationAttr->getAsBlock())
        if (!Location->empty() && (*Location)[0] == DW_OP_fbreg)
          Local.FrameOffset =
              decodeSLEB128(Location->data() + 1, nullptr, Location->end());
    if (auto TagOffsetAttr = Die.find(DW_AT_LLVM_tag_offset))
      Local.TagOffset = TagOffsetAttr->getAsUnsignedConstant();

    if (auto Origin =
            Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
      Die = Origin;
    if (auto NameAttr = Die.find(DW_AT_name))
      if (Optional<const char *> Name = NameAttr->getAsCString())
        Local.Name = *Name;
    if (auto Type = Die.getAttributeValueAsReferencedDie(DW_AT_type))
      Local.Size = getTypeSize(Type, getCUAddrSize());
    if (auto DeclFileAttr = Die.find(DW_AT_decl_file)) {
      if (const auto *LT = CU->getContext().getLineTableForUnit(CU))
        LT->getFileNameByIndex(
            DeclFileAttr->getAsUnsignedConstant().getValue(),
            CU->getCompilationDir(),
            DILineInfoSpecifier::FileLineInfoKind::AbsoluteFilePath,
            Local.DeclFile);
    }
    if (auto DeclLineAttr = Die.find(DW_AT_decl_line))
      Local.DeclLine = DeclLineAttr->getAsUnsignedConstant().getValue();

    Result.push_back(Local);
    return;
  }

  if (Die.getTag() == DW_TAG_inlined_subroutine)
    if (auto Origin =
            Die.getAttributeValueAsReferencedDie(DW_AT_abstract_origin))
      Subprogram = Origin;

  for (auto Child : Die)
    addLocalsForDie(CU, Subprogram, Child, Result);
}

std::vector<DILocal>
DWARFContext::getLocalsForAddress(object::SectionedAddress Address) {
  std::vector<DILocal> Result;
  DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
  if (!CU)
    return Result;

  DWARFDie Subprogram = CU->getSubroutineForAddress(Address.Address);
  if (Subprogram.isValid())
    addLocalsForDie(CU, Subprogram, Subprogram, Result);
  return Result;
}

DILineInfo DWARFContext::getLineInfoForAddress(object::SectionedAddress Address,
                                               DILineInfoSpecifier Spec) {
  DILineInfo Result;

  DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
  if (!CU)
    return Result;

  getFunctionNameAndStartLineForAddress(CU, Address.Address, Spec.FNKind,
                                        Result.FunctionName, Result.StartLine);
  if (Spec.FLIKind != FileLineInfoKind::None) {
    if (const DWARFLineTable *LineTable = getLineTableForUnit(CU)) {
      LineTable->getFileLineInfoForAddress(
          {Address.Address, Address.SectionIndex}, CU->getCompilationDir(),
          Spec.FLIKind, Result);
    }
  }
  return Result;
}

DILineInfoTable DWARFContext::getLineInfoForAddressRange(
    object::SectionedAddress Address, uint64_t Size, DILineInfoSpecifier Spec) {
  DILineInfoTable  Lines;
  DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
  if (!CU)
    return Lines;

  std::string FunctionName = "<invalid>";
  uint32_t StartLine = 0;
  getFunctionNameAndStartLineForAddress(CU, Address.Address, Spec.FNKind,
                                        FunctionName, StartLine);

  // If the Specifier says we don't need FileLineInfo, just
  // return the top-most function at the starting address.
  if (Spec.FLIKind == FileLineInfoKind::None) {
    DILineInfo Result;
    Result.FunctionName = FunctionName;
    Result.StartLine = StartLine;
    Lines.push_back(std::make_pair(Address.Address, Result));
    return Lines;
  }

  const DWARFLineTable *LineTable = getLineTableForUnit(CU);

  // Get the index of row we're looking for in the line table.
  std::vector<uint32_t> RowVector;
  if (!LineTable->lookupAddressRange({Address.Address, Address.SectionIndex},
                                     Size, RowVector)) {
    return Lines;
  }

  for (uint32_t RowIndex : RowVector) {
    // Take file number and line/column from the row.
    const DWARFDebugLine::Row &Row = LineTable->Rows[RowIndex];
    DILineInfo Result;
    LineTable->getFileNameByIndex(Row.File, CU->getCompilationDir(),
                                  Spec.FLIKind, Result.FileName);
    Result.FunctionName = FunctionName;
    Result.Line = Row.Line;
    Result.Column = Row.Column;
    Result.StartLine = StartLine;
    Lines.push_back(std::make_pair(Row.Address.Address, Result));
  }

  return Lines;
}

DIInliningInfo
DWARFContext::getInliningInfoForAddress(object::SectionedAddress Address,
                                        DILineInfoSpecifier Spec) {
  DIInliningInfo InliningInfo;

  DWARFCompileUnit *CU = getCompileUnitForAddress(Address.Address);
  if (!CU)
    return InliningInfo;

  const DWARFLineTable *LineTable = nullptr;
  SmallVector<DWARFDie, 4> InlinedChain;
  CU->getInlinedChainForAddress(Address.Address, InlinedChain);
  if (InlinedChain.size() == 0) {
    // If there is no DIE for address (e.g. it is in unavailable .dwo file),
    // try to at least get file/line info from symbol table.
    if (Spec.FLIKind != FileLineInfoKind::None) {
      DILineInfo Frame;
      LineTable = getLineTableForUnit(CU);
      if (LineTable && LineTable->getFileLineInfoForAddress(
                           {Address.Address, Address.SectionIndex},
                           CU->getCompilationDir(), Spec.FLIKind, Frame))
        InliningInfo.addFrame(Frame);
    }
    return InliningInfo;
  }

  uint32_t CallFile = 0, CallLine = 0, CallColumn = 0, CallDiscriminator = 0;
  for (uint32_t i = 0, n = InlinedChain.size(); i != n; i++) {
    DWARFDie &FunctionDIE = InlinedChain[i];
    DILineInfo Frame;
    // Get function name if necessary.
    if (const char *Name = FunctionDIE.getSubroutineName(Spec.FNKind))
      Frame.FunctionName = Name;
    if (auto DeclLineResult = FunctionDIE.getDeclLine())
      Frame.StartLine = DeclLineResult;
    if (Spec.FLIKind != FileLineInfoKind::None) {
      if (i == 0) {
        // For the topmost frame, initialize the line table of this
        // compile unit and fetch file/line info from it.
        LineTable = getLineTableForUnit(CU);
        // For the topmost routine, get file/line info from line table.
        if (LineTable)
          LineTable->getFileLineInfoForAddress(
              {Address.Address, Address.SectionIndex}, CU->getCompilationDir(),
              Spec.FLIKind, Frame);
      } else {
        // Otherwise, use call file, call line and call column from
        // previous DIE in inlined chain.
        if (LineTable)
          LineTable->getFileNameByIndex(CallFile, CU->getCompilationDir(),
                                        Spec.FLIKind, Frame.FileName);
        Frame.Line = CallLine;
        Frame.Column = CallColumn;
        Frame.Discriminator = CallDiscriminator;
      }
      // Get call file/line/column of a current DIE.
      if (i + 1 < n) {
        FunctionDIE.getCallerFrame(CallFile, CallLine, CallColumn,
                                   CallDiscriminator);
      }
    }
    InliningInfo.addFrame(Frame);
  }
  return InliningInfo;
}

std::shared_ptr<DWARFContext>
DWARFContext::getDWOContext(StringRef AbsolutePath) {
  if (auto S = DWP.lock()) {
    DWARFContext *Ctxt = S->Context.get();
    return std::shared_ptr<DWARFContext>(std::move(S), Ctxt);
  }

  std::weak_ptr<DWOFile> *Entry = &DWOFiles[AbsolutePath];

  if (auto S = Entry->lock()) {
    DWARFContext *Ctxt = S->Context.get();
    return std::shared_ptr<DWARFContext>(std::move(S), Ctxt);
  }

  Expected<OwningBinary<ObjectFile>> Obj = [&] {
    if (!CheckedForDWP) {
      SmallString<128> DWPName;
      auto Obj = object::ObjectFile::createObjectFile(
          this->DWPName.empty()
              ? (DObj->getFileName() + ".dwp").toStringRef(DWPName)
              : StringRef(this->DWPName));
      if (Obj) {
        Entry = &DWP;
        return Obj;
      } else {
        CheckedForDWP = true;
        // TODO: Should this error be handled (maybe in a high verbosity mode)
        // before falling back to .dwo files?
        consumeError(Obj.takeError());
      }
    }

    return object::ObjectFile::createObjectFile(AbsolutePath);
  }();

  if (!Obj) {
    // TODO: Actually report errors helpfully.
    consumeError(Obj.takeError());
    return nullptr;
  }

  auto S = std::make_shared<DWOFile>();
  S->File = std::move(Obj.get());
  S->Context = DWARFContext::create(*S->File.getBinary());
  *Entry = S;
  auto *Ctxt = S->Context.get();
  return std::shared_ptr<DWARFContext>(std::move(S), Ctxt);
}

static Error createError(const Twine &Reason, llvm::Error E) {
  return make_error<StringError>(Reason + toString(std::move(E)),
                                 inconvertibleErrorCode());
}

/// SymInfo contains information about symbol: it's address
/// and section index which is -1LL for absolute symbols.
struct SymInfo {
  uint64_t Address;
  uint64_t SectionIndex;
};

/// Returns the address of symbol relocation used against and a section index.
/// Used for futher relocations computation. Symbol's section load address is
static Expected<SymInfo> getSymbolInfo(const object::ObjectFile &Obj,
                                       const RelocationRef &Reloc,
                                       const LoadedObjectInfo *L,
                                       std::map<SymbolRef, SymInfo> &Cache) {
  SymInfo Ret = {0, (uint64_t)-1LL};
  object::section_iterator RSec = Obj.section_end();
  object::symbol_iterator Sym = Reloc.getSymbol();

  std::map<SymbolRef, SymInfo>::iterator CacheIt = Cache.end();
  // First calculate the address of the symbol or section as it appears
  // in the object file
  if (Sym != Obj.symbol_end()) {
    bool New;
    std::tie(CacheIt, New) = Cache.insert({*Sym, {0, 0}});
    if (!New)
      return CacheIt->second;

    Expected<uint64_t> SymAddrOrErr = Sym->getAddress();
    if (!SymAddrOrErr)
      return createError("failed to compute symbol address: ",
                         SymAddrOrErr.takeError());

    // Also remember what section this symbol is in for later
    auto SectOrErr = Sym->getSection();
    if (!SectOrErr)
      return createError("failed to get symbol section: ",
                         SectOrErr.takeError());

    RSec = *SectOrErr;
    Ret.Address = *SymAddrOrErr;
  } else if (auto *MObj = dyn_cast<MachOObjectFile>(&Obj)) {
    RSec = MObj->getRelocationSection(Reloc.getRawDataRefImpl());
    Ret.Address = RSec->getAddress();
  }

  if (RSec != Obj.section_end())
    Ret.SectionIndex = RSec->getIndex();

  // If we are given load addresses for the sections, we need to adjust:
  // SymAddr = (Address of Symbol Or Section in File) -
  //           (Address of Section in File) +
  //           (Load Address of Section)
  // RSec is now either the section being targeted or the section
  // containing the symbol being targeted. In either case,
  // we need to perform the same computation.
  if (L && RSec != Obj.section_end())
    if (uint64_t SectionLoadAddress = L->getSectionLoadAddress(*RSec))
      Ret.Address += SectionLoadAddress - RSec->getAddress();

  if (CacheIt != Cache.end())
    CacheIt->second = Ret;

  return Ret;
}

static bool isRelocScattered(const object::ObjectFile &Obj,
                             const RelocationRef &Reloc) {
  const MachOObjectFile *MachObj = dyn_cast<MachOObjectFile>(&Obj);
  if (!MachObj)
    return false;
  // MachO also has relocations that point to sections and
  // scattered relocations.
  auto RelocInfo = MachObj->getRelocation(Reloc.getRawDataRefImpl());
  return MachObj->isRelocationScattered(RelocInfo);
}

ErrorPolicy DWARFContext::defaultErrorHandler(Error E) {
  WithColor::error() << toString(std::move(E)) << '\n';
  return ErrorPolicy::Continue;
}

namespace {
struct DWARFSectionMap final : public DWARFSection {
  RelocAddrMap Relocs;
};

class DWARFObjInMemory final : public DWARFObject {
  bool IsLittleEndian;
  uint8_t AddressSize;
  StringRef FileName;
  const object::ObjectFile *Obj = nullptr;
  std::vector<SectionName> SectionNames;

  using InfoSectionMap = MapVector<object::SectionRef, DWARFSectionMap,
                                   std::map<object::SectionRef, unsigned>>;

  InfoSectionMap InfoSections;
  InfoSectionMap TypesSections;
  InfoSectionMap InfoDWOSections;
  InfoSectionMap TypesDWOSections;

  DWARFSectionMap LocSection;
  DWARFSectionMap LocListsSection;
  DWARFSectionMap LineSection;
  DWARFSectionMap RangeSection;
  DWARFSectionMap RnglistsSection;
  DWARFSectionMap StringOffsetSection;
  DWARFSectionMap LineDWOSection;
  DWARFSectionMap LocDWOSection;
  DWARFSectionMap StringOffsetDWOSection;
  DWARFSectionMap RangeDWOSection;
  DWARFSectionMap RnglistsDWOSection;
  DWARFSectionMap AddrSection;
  DWARFSectionMap AppleNamesSection;
  DWARFSectionMap AppleTypesSection;
  DWARFSectionMap AppleNamespacesSection;
  DWARFSectionMap AppleObjCSection;
  DWARFSectionMap DebugNamesSection;
  DWARFSectionMap PubNamesSection;
  DWARFSectionMap PubTypesSection;
  DWARFSectionMap GnuPubNamesSection;
  DWARFSectionMap GnuPubTypesSection;

  DWARFSectionMap *mapNameToDWARFSection(StringRef Name) {
    return StringSwitch<DWARFSectionMap *>(Name)
        .Case("debug_loc", &LocSection)
        .Case("debug_loclists", &LocListsSection)
        .Case("debug_line", &LineSection)
        .Case("debug_str_offsets", &StringOffsetSection)
        .Case("debug_ranges", &RangeSection)
        .Case("debug_rnglists", &RnglistsSection)
        .Case("debug_loc.dwo", &LocDWOSection)
        .Case("debug_line.dwo", &LineDWOSection)
        .Case("debug_names", &DebugNamesSection)
        .Case("debug_rnglists.dwo", &RnglistsDWOSection)
        .Case("debug_str_offsets.dwo", &StringOffsetDWOSection)
        .Case("debug_addr", &AddrSection)
        .Case("apple_names", &AppleNamesSection)
        .Case("debug_pubnames", &PubNamesSection)
        .Case("debug_pubtypes", &PubTypesSection)
        .Case("debug_gnu_pubnames", &GnuPubNamesSection)
        .Case("debug_gnu_pubtypes", &GnuPubTypesSection)
        .Case("apple_types", &AppleTypesSection)
        .Case("apple_namespaces", &AppleNamespacesSection)
        .Case("apple_namespac", &AppleNamespacesSection)
        .Case("apple_objc", &AppleObjCSection)
        .Default(nullptr);
  }

  StringRef AbbrevSection;
  StringRef ARangeSection;
  StringRef DebugFrameSection;
  StringRef EHFrameSection;
  StringRef StringSection;
  StringRef MacinfoSection;
  StringRef AbbrevDWOSection;
  StringRef StringDWOSection;
  StringRef CUIndexSection;
  StringRef GdbIndexSection;
  StringRef TUIndexSection;
  StringRef LineStringSection;

  // A deque holding section data whose iterators are not invalidated when
  // new decompressed sections are inserted at the end.
  std::deque<SmallString<0>> UncompressedSections;

  StringRef *mapSectionToMember(StringRef Name) {
    if (DWARFSection *Sec = mapNameToDWARFSection(Name))
      return &Sec->Data;
    return StringSwitch<StringRef *>(Name)
        .Case("debug_abbrev", &AbbrevSection)
        .Case("debug_aranges", &ARangeSection)
        .Case("debug_frame", &DebugFrameSection)
        .Case("eh_frame", &EHFrameSection)
        .Case("debug_str", &StringSection)
        .Case("debug_macinfo", &MacinfoSection)
        .Case("debug_abbrev.dwo", &AbbrevDWOSection)
        .Case("debug_str.dwo", &StringDWOSection)
        .Case("debug_cu_index", &CUIndexSection)
        .Case("debug_tu_index", &TUIndexSection)
        .Case("gdb_index", &GdbIndexSection)
        .Case("debug_line_str", &LineStringSection)
        // Any more debug info sections go here.
        .Default(nullptr);
  }

  /// If Sec is compressed section, decompresses and updates its contents
  /// provided by Data. Otherwise leaves it unchanged.
  Error maybeDecompress(const object::SectionRef &Sec, StringRef Name,
                        StringRef &Data) {
    if (!Decompressor::isCompressed(Sec))
      return Error::success();

    Expected<Decompressor> Decompressor =
        Decompressor::create(Name, Data, IsLittleEndian, AddressSize == 8);
    if (!Decompressor)
      return Decompressor.takeError();

    SmallString<0> Out;
    if (auto Err = Decompressor->resizeAndDecompress(Out))
      return Err;

    UncompressedSections.push_back(std::move(Out));
    Data = UncompressedSections.back();

    return Error::success();
  }

public:
  DWARFObjInMemory(const StringMap<std::unique_ptr<MemoryBuffer>> &Sections,
                   uint8_t AddrSize, bool IsLittleEndian)
      : IsLittleEndian(IsLittleEndian) {
    for (const auto &SecIt : Sections) {
      if (StringRef *SectionData = mapSectionToMember(SecIt.first()))
        *SectionData = SecIt.second->getBuffer();
      else if (SecIt.first() == "debug_info")
        // Find debug_info and debug_types data by section rather than name as
        // there are multiple, comdat grouped, of these sections.
        InfoSections[SectionRef()].Data = SecIt.second->getBuffer();
      else if (SecIt.first() == "debug_info.dwo")
        InfoDWOSections[SectionRef()].Data = SecIt.second->getBuffer();
      else if (SecIt.first() == "debug_types")
        TypesSections[SectionRef()].Data = SecIt.second->getBuffer();
      else if (SecIt.first() == "debug_types.dwo")
        TypesDWOSections[SectionRef()].Data = SecIt.second->getBuffer();
    }
  }
  DWARFObjInMemory(const object::ObjectFile &Obj, const LoadedObjectInfo *L,
                   function_ref<ErrorPolicy(Error)> HandleError)
      : IsLittleEndian(Obj.isLittleEndian()),
        AddressSize(Obj.getBytesInAddress()), FileName(Obj.getFileName()),
        Obj(&Obj) {

    StringMap<unsigned> SectionAmountMap;
    for (const SectionRef &Section : Obj.sections()) {
      StringRef Name;
      Section.getName(Name);
      ++SectionAmountMap[Name];
      SectionNames.push_back({ Name, true });

      // Skip BSS and Virtual sections, they aren't interesting.
      if (Section.isBSS() || Section.isVirtual())
        continue;

      // Skip sections stripped by dsymutil.
      if (Section.isStripped())
        continue;

      StringRef Data;
      section_iterator RelocatedSection = Section.getRelocatedSection();
      // Try to obtain an already relocated version of this section.
      // Else use the unrelocated section from the object file. We'll have to
      // apply relocations ourselves later.
      if (!L || !L->getLoadedSectionContents(*RelocatedSection, Data)) {
        Expected<StringRef> E = Section.getContents();
        if (E)
          Data = *E;
        else
          // maybeDecompress below will error.
          consumeError(E.takeError());
      }

      if (auto Err = maybeDecompress(Section, Name, Data)) {
        ErrorPolicy EP = HandleError(createError(
            "failed to decompress '" + Name + "', ", std::move(Err)));
        if (EP == ErrorPolicy::Halt)
          return;
        continue;
      }

      // Compressed sections names in GNU style starts from ".z",
      // at this point section is decompressed and we drop compression prefix.
      Name = Name.substr(
          Name.find_first_not_of("._z")); // Skip ".", "z" and "_" prefixes.

      // Map platform specific debug section names to DWARF standard section
      // names.
      Name = Obj.mapDebugSectionName(Name);

      if (StringRef *SectionData = mapSectionToMember(Name)) {
        *SectionData = Data;
        if (Name == "debug_ranges") {
          // FIXME: Use the other dwo range section when we emit it.
          RangeDWOSection.Data = Data;
        }
      } else if (Name == "debug_info") {
        // Find debug_info and debug_types data by section rather than name as
        // there are multiple, comdat grouped, of these sections.
        InfoSections[Section].Data = Data;
      } else if (Name == "debug_info.dwo") {
        InfoDWOSections[Section].Data = Data;
      } else if (Name == "debug_types") {
        TypesSections[Section].Data = Data;
      } else if (Name == "debug_types.dwo") {
        TypesDWOSections[Section].Data = Data;
      }

      if (RelocatedSection == Obj.section_end())
        continue;

      StringRef RelSecName;
      StringRef RelSecData;
      RelocatedSection->getName(RelSecName);

      // If the section we're relocating was relocated already by the JIT,
      // then we used the relocated version above, so we do not need to process
      // relocations for it now.
      if (L && L->getLoadedSectionContents(*RelocatedSection, RelSecData))
        continue;

      // In Mach-o files, the relocations do not need to be applied if
      // there is no load offset to apply. The value read at the
      // relocation point already factors in the section address
      // (actually applying the relocations will produce wrong results
      // as the section address will be added twice).
      if (!L && isa<MachOObjectFile>(&Obj))
        continue;

      RelSecName = RelSecName.substr(
          RelSecName.find_first_not_of("._z")); // Skip . and _ prefixes.

      // TODO: Add support for relocations in other sections as needed.
      // Record relocations for the debug_info and debug_line sections.
      DWARFSectionMap *Sec = mapNameToDWARFSection(RelSecName);
      RelocAddrMap *Map = Sec ? &Sec->Relocs : nullptr;
      if (!Map) {
        // Find debug_info and debug_types relocs by section rather than name
        // as there are multiple, comdat grouped, of these sections.
        if (RelSecName == "debug_info")
          Map = &static_cast<DWARFSectionMap &>(InfoSections[*RelocatedSection])
                     .Relocs;
        else if (RelSecName == "debug_info.dwo")
          Map = &static_cast<DWARFSectionMap &>(
                     InfoDWOSections[*RelocatedSection])
                     .Relocs;
        else if (RelSecName == "debug_types")
          Map =
              &static_cast<DWARFSectionMap &>(TypesSections[*RelocatedSection])
                   .Relocs;
        else if (RelSecName == "debug_types.dwo")
          Map = &static_cast<DWARFSectionMap &>(
                     TypesDWOSections[*RelocatedSection])
                     .Relocs;
        else
          continue;
      }

      if (Section.relocation_begin() == Section.relocation_end())
        continue;

      // Symbol to [address, section index] cache mapping.
      std::map<SymbolRef, SymInfo> AddrCache;
      bool (*Supports)(uint64_t);
      RelocationResolver Resolver;
      std::tie(Supports, Resolver) = getRelocationResolver(Obj);
      for (const RelocationRef &Reloc : Section.relocations()) {
        // FIXME: it's not clear how to correctly handle scattered
        // relocations.
        if (isRelocScattered(Obj, Reloc))
          continue;

        Expected<SymInfo> SymInfoOrErr =
            getSymbolInfo(Obj, Reloc, L, AddrCache);
        if (!SymInfoOrErr) {
          if (HandleError(SymInfoOrErr.takeError()) == ErrorPolicy::Halt)
            return;
          continue;
        }

        // Check if Resolver can handle this relocation type early so as not to
        // handle invalid cases in DWARFDataExtractor.
        //
        // TODO Don't store Resolver in every RelocAddrEntry.
        if (Supports && Supports(Reloc.getType())) {
          auto I = Map->try_emplace(
              Reloc.getOffset(),
              RelocAddrEntry{SymInfoOrErr->SectionIndex, Reloc,
                             SymInfoOrErr->Address,
                             Optional<object::RelocationRef>(), 0, Resolver});
          // If we didn't successfully insert that's because we already had a
          // relocation for that offset. Store it as a second relocation in the
          // same RelocAddrEntry instead.
          if (!I.second) {
            RelocAddrEntry &entry = I.first->getSecond();
            if (entry.Reloc2) {
              ErrorPolicy EP = HandleError(createError(
                  "At most two relocations per offset are supported"));
              if (EP == ErrorPolicy::Halt)
                return;
            }
            entry.Reloc2 = Reloc;
            entry.SymbolValue2 = SymInfoOrErr->Address;
          }
        } else {
          SmallString<32> Type;
          Reloc.getTypeName(Type);
          ErrorPolicy EP = HandleError(
              createError("failed to compute relocation: " + Type + ", ",
                          errorCodeToError(object_error::parse_failed)));
          if (EP == ErrorPolicy::Halt)
            return;
        }
      }
    }

    for (SectionName &S : SectionNames)
      if (SectionAmountMap[S.Name] > 1)
        S.IsNameUnique = false;
  }

  Optional<RelocAddrEntry> find(const DWARFSection &S,
                                uint64_t Pos) const override {
    auto &Sec = static_cast<const DWARFSectionMap &>(S);
    RelocAddrMap::const_iterator AI = Sec.Relocs.find(Pos);
    if (AI == Sec.Relocs.end())
      return None;
    return AI->second;
  }

  const object::ObjectFile *getFile() const override { return Obj; }

  ArrayRef<SectionName> getSectionNames() const override {
    return SectionNames;
  }

  bool isLittleEndian() const override { return IsLittleEndian; }
  StringRef getAbbrevDWOSection() const override { return AbbrevDWOSection; }
  const DWARFSection &getLineDWOSection() const override {
    return LineDWOSection;
  }
  const DWARFSection &getLocDWOSection() const override {
    return LocDWOSection;
  }
  StringRef getStringDWOSection() const override { return StringDWOSection; }
  const DWARFSection &getStringOffsetDWOSection() const override {
    return StringOffsetDWOSection;
  }
  const DWARFSection &getRangeDWOSection() const override {
    return RangeDWOSection;
  }
  const DWARFSection &getRnglistsDWOSection() const override {
    return RnglistsDWOSection;
  }
  const DWARFSection &getAddrSection() const override { return AddrSection; }
  StringRef getCUIndexSection() const override { return CUIndexSection; }
  StringRef getGdbIndexSection() const override { return GdbIndexSection; }
  StringRef getTUIndexSection() const override { return TUIndexSection; }

  // DWARF v5
  const DWARFSection &getStringOffsetSection() const override {
    return StringOffsetSection;
  }
  StringRef getLineStringSection() const override { return LineStringSection; }

  // Sections for DWARF5 split dwarf proposal.
  void forEachInfoDWOSections(
      function_ref<void(const DWARFSection &)> F) const override {
    for (auto &P : InfoDWOSections)
      F(P.second);
  }
  void forEachTypesDWOSections(
      function_ref<void(const DWARFSection &)> F) const override {
    for (auto &P : TypesDWOSections)
      F(P.second);
  }

  StringRef getAbbrevSection() const override { return AbbrevSection; }
  const DWARFSection &getLocSection() const override { return LocSection; }
  const DWARFSection &getLoclistsSection() const override { return LocListsSection; }
  StringRef getARangeSection() const override { return ARangeSection; }
  StringRef getDebugFrameSection() const override { return DebugFrameSection; }
  StringRef getEHFrameSection() const override { return EHFrameSection; }
  const DWARFSection &getLineSection() const override { return LineSection; }
  StringRef getStringSection() const override { return StringSection; }
  const DWARFSection &getRangeSection() const override { return RangeSection; }
  const DWARFSection &getRnglistsSection() const override {
    return RnglistsSection;
  }
  StringRef getMacinfoSection() const override { return MacinfoSection; }
  const DWARFSection &getPubNamesSection() const override { return PubNamesSection; }
  const DWARFSection &getPubTypesSection() const override { return PubTypesSection; }
  const DWARFSection &getGnuPubNamesSection() const override {
    return GnuPubNamesSection;
  }
  const DWARFSection &getGnuPubTypesSection() const override {
    return GnuPubTypesSection;
  }
  const DWARFSection &getAppleNamesSection() const override {
    return AppleNamesSection;
  }
  const DWARFSection &getAppleTypesSection() const override {
    return AppleTypesSection;
  }
  const DWARFSection &getAppleNamespacesSection() const override {
    return AppleNamespacesSection;
  }
  const DWARFSection &getAppleObjCSection() const override {
    return AppleObjCSection;
  }
  const DWARFSection &getDebugNamesSection() const override {
    return DebugNamesSection;
  }

  StringRef getFileName() const override { return FileName; }
  uint8_t getAddressSize() const override { return AddressSize; }
  void forEachInfoSections(
      function_ref<void(const DWARFSection &)> F) const override {
    for (auto &P : InfoSections)
      F(P.second);
  }
  void forEachTypesSections(
      function_ref<void(const DWARFSection &)> F) const override {
    for (auto &P : TypesSections)
      F(P.second);
  }
};
} // namespace

std::unique_ptr<DWARFContext>
DWARFContext::create(const object::ObjectFile &Obj, const LoadedObjectInfo *L,
                     function_ref<ErrorPolicy(Error)> HandleError,
                     std::string DWPName) {
  auto DObj = llvm::make_unique<DWARFObjInMemory>(Obj, L, HandleError);
  return llvm::make_unique<DWARFContext>(std::move(DObj), std::move(DWPName));
}

std::unique_ptr<DWARFContext>
DWARFContext::create(const StringMap<std::unique_ptr<MemoryBuffer>> &Sections,
                     uint8_t AddrSize, bool isLittleEndian) {
  auto DObj =
      llvm::make_unique<DWARFObjInMemory>(Sections, AddrSize, isLittleEndian);
  return llvm::make_unique<DWARFContext>(std::move(DObj), "");
}

Error DWARFContext::loadRegisterInfo(const object::ObjectFile &Obj) {
  // Detect the architecture from the object file. We usually don't need OS
  // info to lookup a target and create register info.
  Triple TT;
  TT.setArch(Triple::ArchType(Obj.getArch()));
  TT.setVendor(Triple::UnknownVendor);
  TT.setOS(Triple::UnknownOS);
  std::string TargetLookupError;
  const Target *TheTarget =
      TargetRegistry::lookupTarget(TT.str(), TargetLookupError);
  if (!TargetLookupError.empty())
    return createStringError(errc::invalid_argument,
                             TargetLookupError.c_str());
  RegInfo.reset(TheTarget->createMCRegInfo(TT.str()));
  return Error::success();
}

uint8_t DWARFContext::getCUAddrSize() {
  // In theory, different compile units may have different address byte
  // sizes, but for simplicity we just use the address byte size of the
  // last compile unit. In practice the address size field is repeated across
  // various DWARF headers (at least in version 5) to make it easier to dump
  // them independently, not to enable varying the address size.
  uint8_t Addr = 0;
  for (const auto &CU : compile_units()) {
    Addr = CU->getAddressByteSize();
    break;
  }
  return Addr;
}

void DWARFContext::dumpWarning(Error Warning) {
  handleAllErrors(std::move(Warning), [](ErrorInfoBase &Info) {
      WithColor::warning() << Info.message() << '\n';
  });
}