llvm.org GIT mirror llvm / 1b27914 include / llvm / IR / DebugInfo.h
1b27914

Tree @1b27914 (Download .tar.gz)

DebugInfo.h @1b27914raw · 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
//===- DebugInfo.h - Debug Information Helpers ------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines a bunch of datatypes that are useful for creating and
// walking debug info in LLVM IR form. They essentially provide wrappers around
// the information in the global variables that's needed when constructing the
// DWARF information.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_IR_DEBUGINFO_H
#define LLVM_IR_DEBUGINFO_H

#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/iterator_range.h"
#include "llvm/IR/Metadata.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Dwarf.h"
#include "llvm/Support/ErrorHandling.h"
#include <iterator>

namespace llvm {
class BasicBlock;
class Constant;
class Function;
class GlobalVariable;
class Module;
class Type;
class Value;
class DbgDeclareInst;
class DbgValueInst;
class Instruction;
class Metadata;
class MDNode;
class MDString;
class NamedMDNode;
class LLVMContext;
class raw_ostream;

class DIFile;
class DISubprogram;
class DILexicalBlock;
class DILexicalBlockFile;
class DIVariable;
class DIType;
class DIScope;
class DIObjCProperty;

/// \brief Maps from type identifier to the actual MDNode.
typedef DenseMap<const MDString *, MDNode *> DITypeIdentifierMap;

class DIHeaderFieldIterator
    : public std::iterator<std::input_iterator_tag, StringRef, std::ptrdiff_t,
                           const StringRef *, StringRef> {
  StringRef Header;
  StringRef Current;

public:
  DIHeaderFieldIterator() {}
  DIHeaderFieldIterator(StringRef Header)
      : Header(Header), Current(Header.slice(0, Header.find('\0'))) {}
  StringRef operator*() const { return Current; }
  const StringRef * operator->() const { return &Current; }
  DIHeaderFieldIterator &operator++() {
    increment();
    return *this;
  }
  DIHeaderFieldIterator operator++(int) {
    DIHeaderFieldIterator X(*this);
    increment();
    return X;
  }
  bool operator==(const DIHeaderFieldIterator &X) const {
    return Current.data() == X.Current.data();
  }
  bool operator!=(const DIHeaderFieldIterator &X) const {
    return !(*this == X);
  }

  StringRef getHeader() const { return Header; }
  StringRef getCurrent() const { return Current; }
  StringRef getPrefix() const {
    if (Current.begin() == Header.begin())
      return StringRef();
    return Header.slice(0, Current.begin() - Header.begin() - 1);
  }
  StringRef getSuffix() const {
    if (Current.end() == Header.end())
      return StringRef();
    return Header.slice(Current.end() - Header.begin() + 1, StringRef::npos);
  }

private:
  void increment() {
    assert(Current.data() != nullptr && "Cannot increment past the end");
    StringRef Suffix = getSuffix();
    Current = Suffix.slice(0, Suffix.find('\0'));
  }
};

/// \brief A thin wraper around MDNode to access encoded debug info.
///
/// This should not be stored in a container, because the underlying MDNode may
/// change in certain situations.
class DIDescriptor {
  // Befriends DIRef so DIRef can befriend the protected member
  // function: getFieldAs<DIRef>.
  template <typename T> friend class DIRef;

public:
  /// \brief Accessibility flags.
  ///
  /// The three accessibility flags are mutually exclusive and rolled together
  /// in the first two bits.
  enum {
    FlagAccessibility     = 1 << 0 | 1 << 1,
    FlagPrivate           = 1,
    FlagProtected         = 2,
    FlagPublic            = 3,

    FlagFwdDecl           = 1 << 2,
    FlagAppleBlock        = 1 << 3,
    FlagBlockByrefStruct  = 1 << 4,
    FlagVirtual           = 1 << 5,
    FlagArtificial        = 1 << 6,
    FlagExplicit          = 1 << 7,
    FlagPrototyped        = 1 << 8,
    FlagObjcClassComplete = 1 << 9,
    FlagObjectPointer     = 1 << 10,
    FlagVector            = 1 << 11,
    FlagStaticMember      = 1 << 12,
    FlagIndirectVariable  = 1 << 13,
    FlagLValueReference   = 1 << 14,
    FlagRValueReference   = 1 << 15
  };

protected:
  const MDNode *DbgNode;

  StringRef getStringField(unsigned Elt) const;
  unsigned getUnsignedField(unsigned Elt) const {
    return (unsigned)getUInt64Field(Elt);
  }
  uint64_t getUInt64Field(unsigned Elt) const;
  int64_t getInt64Field(unsigned Elt) const;
  DIDescriptor getDescriptorField(unsigned Elt) const;

  template <typename DescTy> DescTy getFieldAs(unsigned Elt) const {
    return DescTy(getDescriptorField(Elt));
  }

  GlobalVariable *getGlobalVariableField(unsigned Elt) const;
  Constant *getConstantField(unsigned Elt) const;
  Function *getFunctionField(unsigned Elt) const;
  void replaceFunctionField(unsigned Elt, Function *F);

public:
  explicit DIDescriptor(const MDNode *N = nullptr) : DbgNode(N) {}

  bool Verify() const;

  MDNode *get() const { return const_cast<MDNode *>(DbgNode); }
  operator MDNode *() const { return get(); }
  MDNode *operator->() const { return get(); }

  // An explicit operator bool so that we can do testing of DI values
  // easily.
  // FIXME: This operator bool isn't actually protecting anything at the
  // moment due to the conversion operator above making DIDescriptor nodes
  // implicitly convertable to bool.
  LLVM_EXPLICIT operator bool() const { return DbgNode != nullptr; }

  bool operator==(DIDescriptor Other) const { return DbgNode == Other.DbgNode; }
  bool operator!=(DIDescriptor Other) const { return !operator==(Other); }

  StringRef getHeader() const {
    return getStringField(0);
  }

  size_t getNumHeaderFields() const {
    return std::distance(DIHeaderFieldIterator(getHeader()),
                         DIHeaderFieldIterator());
  }

  StringRef getHeaderField(unsigned Index) const {
    // Since callers expect an empty string for out-of-range accesses, we can't
    // use std::advance() here.
    for (DIHeaderFieldIterator I(getHeader()), E; I != E; ++I, --Index)
      if (!Index)
        return *I;
    return StringRef();
  }

  template <class T> T getHeaderFieldAs(unsigned Index) const {
    T Int;
    if (getHeaderField(Index).getAsInteger(0, Int))
      return 0;
    return Int;
  }

  uint16_t getTag() const { return getHeaderFieldAs<uint16_t>(0); }

  bool isDerivedType() const;
  bool isCompositeType() const;
  bool isSubroutineType() const;
  bool isBasicType() const;
  bool isVariable() const;
  bool isSubprogram() const;
  bool isGlobalVariable() const;
  bool isScope() const;
  bool isFile() const;
  bool isCompileUnit() const;
  bool isNameSpace() const;
  bool isLexicalBlockFile() const;
  bool isLexicalBlock() const;
  bool isSubrange() const;
  bool isEnumerator() const;
  bool isType() const;
  bool isTemplateTypeParameter() const;
  bool isTemplateValueParameter() const;
  bool isObjCProperty() const;
  bool isImportedEntity() const;
  bool isExpression() const;

  void print(raw_ostream &OS) const;
  void dump() const;

  /// \brief Replace all uses of debug info referenced by this descriptor.
  void replaceAllUsesWith(LLVMContext &VMContext, DIDescriptor D);
  void replaceAllUsesWith(MDNode *D);
};

/// \brief This is used to represent ranges, for array bounds.
class DISubrange : public DIDescriptor {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DISubrange(const MDNode *N = nullptr) : DIDescriptor(N) {}

  int64_t getLo() const { return getHeaderFieldAs<int64_t>(1); }
  int64_t getCount() const { return getHeaderFieldAs<int64_t>(2); }
  bool Verify() const;
};

/// \brief This descriptor holds an array of nodes with type T.
template <typename T> class DITypedArray : public DIDescriptor {
public:
  explicit DITypedArray(const MDNode *N = nullptr) : DIDescriptor(N) {}
  unsigned getNumElements() const {
    return DbgNode ? DbgNode->getNumOperands() : 0;
  }
  T getElement(unsigned Idx) const {
    return getFieldAs<T>(Idx);
  }
};

typedef DITypedArray<DIDescriptor> DIArray;

/// \brief A wrapper for an enumerator (e.g. X and Y in 'enum {X,Y}').
///
/// FIXME: it seems strange that this doesn't have either a reference to the
/// type/precision or a file/line pair for location info.
class DIEnumerator : public DIDescriptor {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIEnumerator(const MDNode *N = nullptr) : DIDescriptor(N) {}

  StringRef getName() const { return getHeaderField(1); }
  int64_t getEnumValue() const { return getHeaderFieldAs<int64_t>(2); }
  bool Verify() const;
};

template <typename T> class DIRef;
typedef DIRef<DIScope> DIScopeRef;
typedef DIRef<DIType> DITypeRef;
typedef DITypedArray<DITypeRef> DITypeArray;

/// \brief A base class for various scopes.
///
/// Although, implementation-wise, DIScope is the parent class of most
/// other DIxxx classes, including DIType and its descendants, most of
/// DIScope's descendants are not a substitutable subtype of
/// DIScope. The DIDescriptor::isScope() method only is true for
/// DIScopes that are scopes in the strict lexical scope sense
/// (DICompileUnit, DISubprogram, etc.), but not for, e.g., a DIType.
class DIScope : public DIDescriptor {
protected:
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIScope(const MDNode *N = nullptr) : DIDescriptor(N) {}

  /// \brief Get the parent scope.
  ///
  /// Gets the parent scope for this scope node or returns a default
  /// constructed scope.
  DIScopeRef getContext() const;
  /// \brief Get the scope name.
  ///
  /// If the scope node has a name, return that, else return an empty string.
  StringRef getName() const;
  StringRef getFilename() const;
  StringRef getDirectory() const;

  /// \brief Generate a reference to this DIScope.
  ///
  /// Uses the type identifier instead of the actual MDNode if possible, to
  /// help type uniquing.
  DIScopeRef getRef() const;
};

/// \brief Represents reference to a DIDescriptor.
///
/// Abstracts over direct and identifier-based metadata references.
template <typename T> class DIRef {
  template <typename DescTy>
  friend DescTy DIDescriptor::getFieldAs(unsigned Elt) const;
  friend DIScopeRef DIScope::getContext() const;
  friend DIScopeRef DIScope::getRef() const;
  friend class DIType;

  /// \brief Val can be either a MDNode or a MDString.
  ///
  /// In the latter, MDString specifies the type identifier.
  const Metadata *Val;
  explicit DIRef(const Metadata *V);

public:
  T resolve(const DITypeIdentifierMap &Map) const;
  StringRef getName() const;
  operator Metadata *() const { return const_cast<Metadata *>(Val); }
};

template <typename T>
T DIRef<T>::resolve(const DITypeIdentifierMap &Map) const {
  if (!Val)
    return T();

  if (const MDNode *MD = dyn_cast<MDNode>(Val))
    return T(MD);

  const MDString *MS = cast<MDString>(Val);
  // Find the corresponding MDNode.
  DITypeIdentifierMap::const_iterator Iter = Map.find(MS);
  assert(Iter != Map.end() && "Identifier not in the type map?");
  assert(DIDescriptor(Iter->second).isType() &&
         "MDNode in DITypeIdentifierMap should be a DIType.");
  return T(Iter->second);
}

template <typename T> StringRef DIRef<T>::getName() const {
  if (!Val)
    return StringRef();

  if (const MDNode *MD = dyn_cast<MDNode>(Val))
    return T(MD).getName();

  const MDString *MS = cast<MDString>(Val);
  return MS->getString();
}

/// \brief Handle fields that are references to DIScopes.
template <> DIScopeRef DIDescriptor::getFieldAs<DIScopeRef>(unsigned Elt) const;
/// \brief Specialize DIRef constructor for DIScopeRef.
template <> DIRef<DIScope>::DIRef(const Metadata *V);

/// \brief Handle fields that are references to DITypes.
template <> DITypeRef DIDescriptor::getFieldAs<DITypeRef>(unsigned Elt) const;
/// \brief Specialize DIRef constructor for DITypeRef.
template <> DIRef<DIType>::DIRef(const Metadata *V);

/// \briefThis is a wrapper for a type.
///
/// FIXME: Types should be factored much better so that CV qualifiers and
/// others do not require a huge and empty descriptor full of zeros.
class DIType : public DIScope {
protected:
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIType(const MDNode *N = nullptr) : DIScope(N) {}
  operator DITypeRef () const {
    assert(isType() &&
           "constructing DITypeRef from an MDNode that is not a type");
    return DITypeRef(&*getRef());
  }

  bool Verify() const;

  DIScopeRef getContext() const { return getFieldAs<DIScopeRef>(2); }
  StringRef getName() const { return getHeaderField(1); }
  unsigned getLineNumber() const {
    return getHeaderFieldAs<unsigned>(2);
  }
  uint64_t getSizeInBits() const {
    return getHeaderFieldAs<unsigned>(3);
  }
  uint64_t getAlignInBits() const {
    return getHeaderFieldAs<unsigned>(4);
  }
  // FIXME: Offset is only used for DW_TAG_member nodes.  Making every type
  // carry this is just plain insane.
  uint64_t getOffsetInBits() const {
    return getHeaderFieldAs<unsigned>(5);
  }
  unsigned getFlags() const { return getHeaderFieldAs<unsigned>(6); }
  bool isPrivate() const {
    return (getFlags() & FlagAccessibility) == FlagPrivate;
  }
  bool isProtected() const {
    return (getFlags() & FlagAccessibility) == FlagProtected;
  }
  bool isPublic() const {
    return (getFlags() & FlagAccessibility) == FlagPublic;
  }
  bool isForwardDecl() const { return (getFlags() & FlagFwdDecl) != 0; }
  bool isAppleBlockExtension() const {
    return (getFlags() & FlagAppleBlock) != 0;
  }
  bool isBlockByrefStruct() const {
    return (getFlags() & FlagBlockByrefStruct) != 0;
  }
  bool isVirtual() const { return (getFlags() & FlagVirtual) != 0; }
  bool isArtificial() const { return (getFlags() & FlagArtificial) != 0; }
  bool isObjectPointer() const { return (getFlags() & FlagObjectPointer) != 0; }
  bool isObjcClassComplete() const {
    return (getFlags() & FlagObjcClassComplete) != 0;
  }
  bool isVector() const { return (getFlags() & FlagVector) != 0; }
  bool isStaticMember() const { return (getFlags() & FlagStaticMember) != 0; }
  bool isLValueReference() const {
    return (getFlags() & FlagLValueReference) != 0;
  }
  bool isRValueReference() const {
    return (getFlags() & FlagRValueReference) != 0;
  }
  bool isValid() const { return DbgNode && isType(); }
};

/// \brief A basic type, like 'int' or 'float'.
class DIBasicType : public DIType {
public:
  explicit DIBasicType(const MDNode *N = nullptr) : DIType(N) {}

  unsigned getEncoding() const { return getHeaderFieldAs<unsigned>(7); }

  bool Verify() const;
};

/// \brief A simple derived type
///
/// Like a const qualified type, a typedef, a pointer or reference, et cetera.
/// Or, a data member of a class/struct/union.
class DIDerivedType : public DIType {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIDerivedType(const MDNode *N = nullptr) : DIType(N) {}

  DITypeRef getTypeDerivedFrom() const { return getFieldAs<DITypeRef>(3); }

  /// \brief Return property node, if this ivar is associated with one.
  MDNode *getObjCProperty() const;

  DITypeRef getClassType() const {
    assert(getTag() == dwarf::DW_TAG_ptr_to_member_type);
    return getFieldAs<DITypeRef>(4);
  }

  Constant *getConstant() const {
    assert((getTag() == dwarf::DW_TAG_member) && isStaticMember());
    return getConstantField(4);
  }

  bool Verify() const;
};

/// \brief Types that refer to multiple other types.
///
/// This descriptor holds a type that can refer to multiple other types, like a
/// function or struct.
///
/// DICompositeType is derived from DIDerivedType because some
/// composite types (such as enums) can be derived from basic types
// FIXME: Make this derive from DIType directly & just store the
// base type in a single DIType field.
class DICompositeType : public DIDerivedType {
  friend class DIBuilder;
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

  /// \brief Set the array of member DITypes.
  void setArraysHelper(MDNode *Elements, MDNode *TParams);

public:
  explicit DICompositeType(const MDNode *N = nullptr) : DIDerivedType(N) {}

  DIArray getElements() const {
    assert(!isSubroutineType() && "no elements for DISubroutineType");
    return getFieldAs<DIArray>(4);
  }

private:
  template <typename T>
  void setArrays(DITypedArray<T> Elements, DIArray TParams = DIArray()) {
    assert((!TParams || DbgNode->getNumOperands() == 8) &&
           "If you're setting the template parameters this should include a slot "
           "for that!");
    setArraysHelper(Elements, TParams);
  }

public:
  unsigned getRunTimeLang() const {
    return getHeaderFieldAs<unsigned>(7);
  }
  DITypeRef getContainingType() const { return getFieldAs<DITypeRef>(5); }

private:
  /// \brief Set the containing type.
  void setContainingType(DICompositeType ContainingType);

public:
  DIArray getTemplateParams() const { return getFieldAs<DIArray>(6); }
  MDString *getIdentifier() const;

  bool Verify() const;
};

class DISubroutineType : public DICompositeType {
public:
  explicit DISubroutineType(const MDNode *N = nullptr) : DICompositeType(N) {}
  DITypedArray<DITypeRef> getTypeArray() const {
    return getFieldAs<DITypedArray<DITypeRef>>(4);
  }
};

/// \brief This is a wrapper for a file.
class DIFile : public DIScope {
  friend class DIDescriptor;

public:
  explicit DIFile(const MDNode *N = nullptr) : DIScope(N) {}

  /// \brief Retrieve the MDNode for the directory/file pair.
  MDNode *getFileNode() const;
  bool Verify() const;
};

/// \brief A wrapper for a compile unit.
class DICompileUnit : public DIScope {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DICompileUnit(const MDNode *N = nullptr) : DIScope(N) {}

  dwarf::SourceLanguage getLanguage() const {
    return static_cast<dwarf::SourceLanguage>(getHeaderFieldAs<unsigned>(1));
  }
  StringRef getProducer() const { return getHeaderField(2); }

  bool isOptimized() const { return getHeaderFieldAs<bool>(3) != 0; }
  StringRef getFlags() const { return getHeaderField(4); }
  unsigned getRunTimeVersion() const { return getHeaderFieldAs<unsigned>(5); }

  DIArray getEnumTypes() const;
  DIArray getRetainedTypes() const;
  DIArray getSubprograms() const;
  DIArray getGlobalVariables() const;
  DIArray getImportedEntities() const;

  void replaceSubprograms(DIArray Subprograms);
  void replaceGlobalVariables(DIArray GlobalVariables);

  StringRef getSplitDebugFilename() const { return getHeaderField(6); }
  unsigned getEmissionKind() const { return getHeaderFieldAs<unsigned>(7); }

  bool Verify() const;
};

/// \brief This is a wrapper for a subprogram (e.g. a function).
class DISubprogram : public DIScope {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DISubprogram(const MDNode *N = nullptr) : DIScope(N) {}

  StringRef getName() const { return getHeaderField(1); }
  StringRef getDisplayName() const { return getHeaderField(2); }
  StringRef getLinkageName() const { return getHeaderField(3); }
  unsigned getLineNumber() const { return getHeaderFieldAs<unsigned>(4); }

  /// \brief Check if this is local (like 'static' in C).
  unsigned isLocalToUnit() const { return getHeaderFieldAs<unsigned>(5); }
  unsigned isDefinition() const { return getHeaderFieldAs<unsigned>(6); }

  unsigned getVirtuality() const { return getHeaderFieldAs<unsigned>(7); }
  unsigned getVirtualIndex() const { return getHeaderFieldAs<unsigned>(8); }

  unsigned getFlags() const { return getHeaderFieldAs<unsigned>(9); }

  unsigned isOptimized() const { return getHeaderFieldAs<bool>(10); }

  /// \brief Get the beginning of the scope of the function (not the name).
  unsigned getScopeLineNumber() const { return getHeaderFieldAs<unsigned>(11); }

  DIScopeRef getContext() const { return getFieldAs<DIScopeRef>(2); }
  DISubroutineType getType() const { return getFieldAs<DISubroutineType>(3); }

  DITypeRef getContainingType() const { return getFieldAs<DITypeRef>(4); }

  bool Verify() const;

  /// \brief Check if this provides debugging information for the function F.
  bool describes(const Function *F);

  Function *getFunction() const { return getFunctionField(5); }
  void replaceFunction(Function *F) { replaceFunctionField(5, F); }
  DIArray getTemplateParams() const { return getFieldAs<DIArray>(6); }
  DISubprogram getFunctionDeclaration() const {
    return getFieldAs<DISubprogram>(7);
  }
  MDNode *getVariablesNodes() const;
  DIArray getVariables() const;

  unsigned isArtificial() const { return (getFlags() & FlagArtificial) != 0; }
  /// \brief Check for the "private" access specifier.
  bool isPrivate() const {
    return (getFlags() & FlagAccessibility) == FlagPrivate;
  }
  /// \brief Check for the "protected" access specifier.
  bool isProtected() const {
    return (getFlags() & FlagAccessibility) == FlagProtected;
  }
  /// \brief Check for the "public" access specifier.
  bool isPublic() const {
    return (getFlags() & FlagAccessibility) == FlagPublic;
  }
  /// \brief Check for "explicit".
  bool isExplicit() const { return (getFlags() & FlagExplicit) != 0; }
  /// \brief Check if this is prototyped.
  bool isPrototyped() const { return (getFlags() & FlagPrototyped) != 0; }

  /// \brief Check if this is reference-qualified.
  ///
  /// Return true if this subprogram is a C++11 reference-qualified non-static
  /// member function (void foo() &).
  unsigned isLValueReference() const {
    return (getFlags() & FlagLValueReference) != 0;
  }

  /// \brief Check if this is rvalue-reference-qualified.
  ///
  /// Return true if this subprogram is a C++11 rvalue-reference-qualified
  /// non-static member function (void foo() &&).
  unsigned isRValueReference() const {
    return (getFlags() & FlagRValueReference) != 0;
  }

};

/// \brief This is a wrapper for a lexical block.
class DILexicalBlock : public DIScope {
public:
  explicit DILexicalBlock(const MDNode *N = nullptr) : DIScope(N) {}
  DIScope getContext() const { return getFieldAs<DIScope>(2); }
  unsigned getLineNumber() const {
    return getHeaderFieldAs<unsigned>(1);
  }
  unsigned getColumnNumber() const {
    return getHeaderFieldAs<unsigned>(2);
  }
  bool Verify() const;
};

/// \brief This is a wrapper for a lexical block with a filename change.
class DILexicalBlockFile : public DIScope {
public:
  explicit DILexicalBlockFile(const MDNode *N = nullptr) : DIScope(N) {}
  DIScope getContext() const {
    if (getScope().isSubprogram())
      return getScope();
    return getScope().getContext();
  }
  unsigned getLineNumber() const { return getScope().getLineNumber(); }
  unsigned getColumnNumber() const { return getScope().getColumnNumber(); }
  DILexicalBlock getScope() const { return getFieldAs<DILexicalBlock>(2); }
  unsigned getDiscriminator() const { return getHeaderFieldAs<unsigned>(1); }
  bool Verify() const;
};

/// \brief A wrapper for a C++ style name space.
class DINameSpace : public DIScope {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DINameSpace(const MDNode *N = nullptr) : DIScope(N) {}
  StringRef getName() const { return getHeaderField(1); }
  unsigned getLineNumber() const { return getHeaderFieldAs<unsigned>(2); }
  DIScope getContext() const { return getFieldAs<DIScope>(2); }
  bool Verify() const;
};

/// \brief This is a wrapper for template type parameter.
class DITemplateTypeParameter : public DIDescriptor {
public:
  explicit DITemplateTypeParameter(const MDNode *N = nullptr)
    : DIDescriptor(N) {}

  StringRef getName() const { return getHeaderField(1); }
  unsigned getLineNumber() const { return getHeaderFieldAs<unsigned>(2); }
  unsigned getColumnNumber() const { return getHeaderFieldAs<unsigned>(3); }

  DIScopeRef getContext() const { return getFieldAs<DIScopeRef>(1); }
  DITypeRef getType() const { return getFieldAs<DITypeRef>(2); }
  StringRef getFilename() const { return getFieldAs<DIFile>(3).getFilename(); }
  StringRef getDirectory() const {
    return getFieldAs<DIFile>(3).getDirectory();
  }
  bool Verify() const;
};

/// \brief This is a wrapper for template value parameter.
class DITemplateValueParameter : public DIDescriptor {
public:
  explicit DITemplateValueParameter(const MDNode *N = nullptr)
    : DIDescriptor(N) {}

  StringRef getName() const { return getHeaderField(1); }
  unsigned getLineNumber() const { return getHeaderFieldAs<unsigned>(2); }
  unsigned getColumnNumber() const { return getHeaderFieldAs<unsigned>(3); }

  DIScopeRef getContext() const { return getFieldAs<DIScopeRef>(1); }
  DITypeRef getType() const { return getFieldAs<DITypeRef>(2); }
  Metadata *getValue() const;
  StringRef getFilename() const { return getFieldAs<DIFile>(4).getFilename(); }
  StringRef getDirectory() const {
    return getFieldAs<DIFile>(4).getDirectory();
  }
  bool Verify() const;
};

/// \brief This is a wrapper for a global variable.
class DIGlobalVariable : public DIDescriptor {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIGlobalVariable(const MDNode *N = nullptr) : DIDescriptor(N) {}

  StringRef getName() const { return getHeaderField(1); }
  StringRef getDisplayName() const { return getHeaderField(2); }
  StringRef getLinkageName() const { return getHeaderField(3); }
  unsigned getLineNumber() const { return getHeaderFieldAs<unsigned>(4); }
  unsigned isLocalToUnit() const { return getHeaderFieldAs<bool>(5); }
  unsigned isDefinition() const { return getHeaderFieldAs<bool>(6); }

  DIScope getContext() const { return getFieldAs<DIScope>(1); }
  StringRef getFilename() const { return getFieldAs<DIFile>(2).getFilename(); }
  StringRef getDirectory() const {
    return getFieldAs<DIFile>(2).getDirectory();
  }
  DITypeRef getType() const { return getFieldAs<DITypeRef>(3); }

  GlobalVariable *getGlobal() const { return getGlobalVariableField(4); }
  Constant *getConstant() const { return getConstantField(4); }
  DIDerivedType getStaticDataMemberDeclaration() const {
    return getFieldAs<DIDerivedType>(5);
  }

  bool Verify() const;
};

/// \brief This is a wrapper for a variable (e.g. parameter, local, global etc).
class DIVariable : public DIDescriptor {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIVariable(const MDNode *N = nullptr) : DIDescriptor(N) {}

  StringRef getName() const { return getHeaderField(1); }
  unsigned getLineNumber() const {
    // FIXME: Line number and arg number shouldn't be merged together like this.
    return (getHeaderFieldAs<unsigned>(2) << 8) >> 8;
  }
  unsigned getArgNumber() const { return getHeaderFieldAs<unsigned>(2) >> 24; }

  DIScope getContext() const { return getFieldAs<DIScope>(1); }
  DIFile getFile() const { return getFieldAs<DIFile>(2); }
  DITypeRef getType() const { return getFieldAs<DITypeRef>(3); }

  /// \brief Return true if this variable is marked as "artificial".
  bool isArtificial() const {
    return (getHeaderFieldAs<unsigned>(3) & FlagArtificial) != 0;
  }

  bool isObjectPointer() const {
    return (getHeaderFieldAs<unsigned>(3) & FlagObjectPointer) != 0;
  }

  /// \brief Return true if this variable is represented as a pointer.
  bool isIndirect() const {
    return (getHeaderFieldAs<unsigned>(3) & FlagIndirectVariable) != 0;
  }

  /// \brief If this variable is inlined then return inline location.
  MDNode *getInlinedAt() const;

  bool Verify() const;

  /// \brief Check if this is a "__block" variable (Apple Blocks).
  bool isBlockByrefVariable(const DITypeIdentifierMap &Map) const {
    return (getType().resolve(Map)).isBlockByrefStruct();
  }

  /// \brief Check if this is an inlined function argument.
  bool isInlinedFnArgument(const Function *CurFn);

  /// \brief Return the size reported by the variable's type.
  unsigned getSizeInBits(const DITypeIdentifierMap &Map);

  void printExtendedName(raw_ostream &OS) const;
};

/// \brief A complex location expression.
class DIExpression : public DIDescriptor {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIExpression(const MDNode *N = nullptr) : DIDescriptor(N) {}

  bool Verify() const;

  /// \brief Return the number of elements in the complex expression.
  unsigned getNumElements() const {
    if (!DbgNode)
      return 0;
    unsigned N = getNumHeaderFields();
    assert(N > 0 && "missing tag");
    return N - 1;
  }

  /// \brief return the Idx'th complex address element.
  uint64_t getElement(unsigned Idx) const;

  /// \brief Return whether this is a piece of an aggregate variable.
  bool isVariablePiece() const;
  /// \brief Return the offset of this piece in bytes.
  uint64_t getPieceOffset() const;
  /// \brief Return the size of this piece in bytes.
  uint64_t getPieceSize() const;
};

/// \brief This object holds location information.
///
/// This object is not associated with any DWARF tag.
class DILocation : public DIDescriptor {
public:
  explicit DILocation(const MDNode *N) : DIDescriptor(N) {}

  unsigned getLineNumber() const { return getUnsignedField(0); }
  unsigned getColumnNumber() const { return getUnsignedField(1); }
  DIScope getScope() const { return getFieldAs<DIScope>(2); }
  DILocation getOrigLocation() const { return getFieldAs<DILocation>(3); }
  StringRef getFilename() const { return getScope().getFilename(); }
  StringRef getDirectory() const { return getScope().getDirectory(); }
  bool Verify() const;
  bool atSameLineAs(const DILocation &Other) const {
    return (getLineNumber() == Other.getLineNumber() &&
            getFilename() == Other.getFilename());
  }
  /// \brief Get the DWAF discriminator.
  ///
  /// DWARF discriminators are used to distinguish identical file locations for
  /// instructions that are on different basic blocks. If two instructions are
  /// inside the same lexical block and are in different basic blocks, we
  /// create a new lexical block with identical location as the original but
  /// with a different discriminator value
  /// (lib/Transforms/Util/AddDiscriminators.cpp for details).
  unsigned getDiscriminator() const {
    // Since discriminators are associated with lexical blocks, make
    // sure this location is a lexical block before retrieving its
    // value.
    return getScope().isLexicalBlockFile()
               ? getFieldAs<DILexicalBlockFile>(2).getDiscriminator()
               : 0;
  }

  /// \brief Generate a new discriminator value for this location.
  unsigned computeNewDiscriminator(LLVMContext &Ctx);

  /// \brief Return a copy of this location with a different scope.
  DILocation copyWithNewScope(LLVMContext &Ctx, DILexicalBlockFile NewScope);
};

class DIObjCProperty : public DIDescriptor {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIObjCProperty(const MDNode *N) : DIDescriptor(N) {}

  StringRef getObjCPropertyName() const { return getHeaderField(1); }
  DIFile getFile() const { return getFieldAs<DIFile>(1); }
  unsigned getLineNumber() const { return getHeaderFieldAs<unsigned>(2); }

  StringRef getObjCPropertyGetterName() const { return getHeaderField(3); }
  StringRef getObjCPropertySetterName() const { return getHeaderField(4); }
  unsigned getAttributes() const { return getHeaderFieldAs<unsigned>(5); }
  bool isReadOnlyObjCProperty() const {
    return (getAttributes() & dwarf::DW_APPLE_PROPERTY_readonly) != 0;
  }
  bool isReadWriteObjCProperty() const {
    return (getAttributes() & dwarf::DW_APPLE_PROPERTY_readwrite) != 0;
  }
  bool isAssignObjCProperty() const {
    return (getAttributes() & dwarf::DW_APPLE_PROPERTY_assign) != 0;
  }
  bool isRetainObjCProperty() const {
    return (getAttributes() & dwarf::DW_APPLE_PROPERTY_retain) != 0;
  }
  bool isCopyObjCProperty() const {
    return (getAttributes() & dwarf::DW_APPLE_PROPERTY_copy) != 0;
  }
  bool isNonAtomicObjCProperty() const {
    return (getAttributes() & dwarf::DW_APPLE_PROPERTY_nonatomic) != 0;
  }

  /// \brief Get the type.
  ///
  /// \note Objective-C doesn't have an ODR, so there is no benefit in storing
  /// the type as a DITypeRef here.
  DIType getType() const { return getFieldAs<DIType>(2); }

  bool Verify() const;
};

/// \brief An imported module (C++ using directive or similar).
class DIImportedEntity : public DIDescriptor {
  friend class DIDescriptor;
  void printInternal(raw_ostream &OS) const;

public:
  explicit DIImportedEntity(const MDNode *N) : DIDescriptor(N) {}
  DIScope getContext() const { return getFieldAs<DIScope>(1); }
  DIScopeRef getEntity() const { return getFieldAs<DIScopeRef>(2); }
  unsigned getLineNumber() const { return getHeaderFieldAs<unsigned>(1); }
  StringRef getName() const { return getHeaderField(2); }
  bool Verify() const;
};

/// \brief Find subprogram that is enclosing this scope.
DISubprogram getDISubprogram(const MDNode *Scope);

/// \brief Find debug info for a given function.
/// \returns a valid DISubprogram, if found. Otherwise, it returns an empty
/// DISubprogram.
DISubprogram getDISubprogram(const Function *F);

/// \brief Find underlying composite type.
DICompositeType getDICompositeType(DIType T);

/// \brief Create a new inlined variable based on current variable.
///
/// @param DV            Current Variable.
/// @param InlinedScope  Location at current variable is inlined.
DIVariable createInlinedVariable(MDNode *DV, MDNode *InlinedScope,
                                 LLVMContext &VMContext);

/// \brief Remove inlined scope from the variable.
DIVariable cleanseInlinedVariable(MDNode *DV, LLVMContext &VMContext);

/// \brief Generate map by visiting all retained types.
DITypeIdentifierMap generateDITypeIdentifierMap(const NamedMDNode *CU_Nodes);

/// \brief Strip debug info in the module if it exists.
///
/// To do this, we remove all calls to the debugger intrinsics and any named
/// metadata for debugging. We also remove debug locations for instructions.
/// Return true if module is modified.
bool StripDebugInfo(Module &M);

/// \brief Return Debug Info Metadata Version by checking module flags.
unsigned getDebugMetadataVersionFromModule(const Module &M);

/// \brief Utility to find all debug info in a module.
///
/// DebugInfoFinder tries to list all debug info MDNodes used in a module. To
/// list debug info MDNodes used by an instruction, DebugInfoFinder uses
/// processDeclare, processValue and processLocation to handle DbgDeclareInst,
/// DbgValueInst and DbgLoc attached to instructions. processModule will go
/// through all DICompileUnits in llvm.dbg.cu and list debug info MDNodes
/// used by the CUs.
class DebugInfoFinder {
public:
  DebugInfoFinder() : TypeMapInitialized(false) {}

  /// \brief Process entire module and collect debug info anchors.
  void processModule(const Module &M);

  /// \brief Process DbgDeclareInst.
  void processDeclare(const Module &M, const DbgDeclareInst *DDI);
  /// \brief Process DbgValueInst.
  void processValue(const Module &M, const DbgValueInst *DVI);
  /// \brief Process DILocation.
  void processLocation(const Module &M, DILocation Loc);

  /// \brief Clear all lists.
  void reset();

private:
  void InitializeTypeMap(const Module &M);

  void processType(DIType DT);
  void processSubprogram(DISubprogram SP);
  void processScope(DIScope Scope);
  bool addCompileUnit(DICompileUnit CU);
  bool addGlobalVariable(DIGlobalVariable DIG);
  bool addSubprogram(DISubprogram SP);
  bool addType(DIType DT);
  bool addScope(DIScope Scope);

public:
  typedef SmallVectorImpl<DICompileUnit>::const_iterator compile_unit_iterator;
  typedef SmallVectorImpl<DISubprogram>::const_iterator subprogram_iterator;
  typedef SmallVectorImpl<DIGlobalVariable>::const_iterator global_variable_iterator;
  typedef SmallVectorImpl<DIType>::const_iterator type_iterator;
  typedef SmallVectorImpl<DIScope>::const_iterator scope_iterator;

  iterator_range<compile_unit_iterator> compile_units() const {
    return iterator_range<compile_unit_iterator>(CUs.begin(), CUs.end());
  }

  iterator_range<subprogram_iterator> subprograms() const {
    return iterator_range<subprogram_iterator>(SPs.begin(), SPs.end());
  }

  iterator_range<global_variable_iterator> global_variables() const {
    return iterator_range<global_variable_iterator>(GVs.begin(), GVs.end());
  }

  iterator_range<type_iterator> types() const {
    return iterator_range<type_iterator>(TYs.begin(), TYs.end());
  }

  iterator_range<scope_iterator> scopes() const {
    return iterator_range<scope_iterator>(Scopes.begin(), Scopes.end());
  }

  unsigned compile_unit_count() const { return CUs.size(); }
  unsigned global_variable_count() const { return GVs.size(); }
  unsigned subprogram_count() const { return SPs.size(); }
  unsigned type_count() const { return TYs.size(); }
  unsigned scope_count() const { return Scopes.size(); }

private:
  SmallVector<DICompileUnit, 8> CUs;
  SmallVector<DISubprogram, 8> SPs;
  SmallVector<DIGlobalVariable, 8> GVs;
  SmallVector<DIType, 8> TYs;
  SmallVector<DIScope, 8> Scopes;
  SmallPtrSet<MDNode *, 64> NodesSeen;
  DITypeIdentifierMap TypeIdentifierMap;

  /// \brief Specify if TypeIdentifierMap is initialized.
  bool TypeMapInitialized;
};

DenseMap<const Function *, DISubprogram> makeSubprogramMap(const Module &M);

} // end namespace llvm

#endif