NSDictionary.cpp 31.5 KB
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
//===-- NSDictionary.cpp ----------------------------------------*- C++ -*-===//
//
// 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 <mutex>

#include "clang/AST/DeclCXX.h"

#include "NSDictionary.h"

#include "Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.h"

#include "lldb/Core/ValueObject.h"
#include "lldb/Core/ValueObjectConstResult.h"
#include "lldb/DataFormatters/FormattersHelpers.h"
#include "lldb/Symbol/ClangASTContext.h"
#include "lldb/Target/Language.h"
#include "lldb/Target/StackFrame.h"
#include "lldb/Target/Target.h"
#include "lldb/Utility/DataBufferHeap.h"
#include "lldb/Utility/Endian.h"
#include "lldb/Utility/Status.h"
#include "lldb/Utility/Stream.h"

using namespace lldb;
using namespace lldb_private;
using namespace lldb_private::formatters;

NSDictionary_Additionals::AdditionalFormatterMatching::Prefix::Prefix(
    ConstString p)
    : m_prefix(p) {}

bool NSDictionary_Additionals::AdditionalFormatterMatching::Prefix::Match(
    ConstString class_name) {
  return class_name.GetStringRef().startswith(m_prefix.GetStringRef());
}

NSDictionary_Additionals::AdditionalFormatterMatching::Full::Full(ConstString n)
    : m_name(n) {}

bool NSDictionary_Additionals::AdditionalFormatterMatching::Full::Match(
    ConstString class_name) {
  return (class_name == m_name);
}

NSDictionary_Additionals::AdditionalFormatters<
    CXXFunctionSummaryFormat::Callback> &
NSDictionary_Additionals::GetAdditionalSummaries() {
  static AdditionalFormatters<CXXFunctionSummaryFormat::Callback> g_map;
  return g_map;
}

NSDictionary_Additionals::AdditionalFormatters<
    CXXSyntheticChildren::CreateFrontEndCallback> &
NSDictionary_Additionals::GetAdditionalSynthetics() {
  static AdditionalFormatters<CXXSyntheticChildren::CreateFrontEndCallback>
      g_map;
  return g_map;
}

static CompilerType GetLLDBNSPairType(TargetSP target_sp) {
  CompilerType compiler_type;

  ClangASTContext *target_ast_context = ClangASTContext::GetScratch(*target_sp);

  if (target_ast_context) {
    ConstString g___lldb_autogen_nspair("__lldb_autogen_nspair");

    compiler_type =
        target_ast_context->GetTypeForIdentifier<clang::CXXRecordDecl>(
            g___lldb_autogen_nspair);

    if (!compiler_type) {
      compiler_type = target_ast_context->CreateRecordType(
          nullptr, lldb::eAccessPublic, g___lldb_autogen_nspair.GetCString(),
          clang::TTK_Struct, lldb::eLanguageTypeC);

      if (compiler_type) {
        ClangASTContext::StartTagDeclarationDefinition(compiler_type);
        CompilerType id_compiler_type =
            target_ast_context->GetBasicType(eBasicTypeObjCID);
        ClangASTContext::AddFieldToRecordType(
            compiler_type, "key", id_compiler_type, lldb::eAccessPublic, 0);
        ClangASTContext::AddFieldToRecordType(
            compiler_type, "value", id_compiler_type, lldb::eAccessPublic, 0);
        ClangASTContext::CompleteTagDeclarationDefinition(compiler_type);
      }
    }
  }
  return compiler_type;
}

namespace lldb_private {
namespace formatters {
class NSDictionaryISyntheticFrontEnd : public SyntheticChildrenFrontEnd {
public:
  NSDictionaryISyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);

  ~NSDictionaryISyntheticFrontEnd() override;

  size_t CalculateNumChildren() override;

  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;

  bool Update() override;

  bool MightHaveChildren() override;

  size_t GetIndexOfChildWithName(ConstString name) override;

private:
  struct DataDescriptor_32 {
    uint32_t _used : 26;
    uint32_t _szidx : 6;
  };

  struct DataDescriptor_64 {
    uint64_t _used : 58;
    uint32_t _szidx : 6;
  };

  struct DictionaryItemDescriptor {
    lldb::addr_t key_ptr;
    lldb::addr_t val_ptr;
    lldb::ValueObjectSP valobj_sp;
  };

  ExecutionContextRef m_exe_ctx_ref;
  uint8_t m_ptr_size;
  lldb::ByteOrder m_order;
  DataDescriptor_32 *m_data_32;
  DataDescriptor_64 *m_data_64;
  lldb::addr_t m_data_ptr;
  CompilerType m_pair_type;
  std::vector<DictionaryItemDescriptor> m_children;
};

class NSDictionary1SyntheticFrontEnd : public SyntheticChildrenFrontEnd {
public:
  NSDictionary1SyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);

  ~NSDictionary1SyntheticFrontEnd() override = default;

  size_t CalculateNumChildren() override;

  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;

  bool Update() override;

  bool MightHaveChildren() override;

  size_t GetIndexOfChildWithName(ConstString name) override;

private:
  ValueObjectSP m_pair;
};

template <typename D32, typename D64>
class GenericNSDictionaryMSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
public:
  GenericNSDictionaryMSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);

  ~GenericNSDictionaryMSyntheticFrontEnd() override;

  size_t CalculateNumChildren() override;

  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;

  bool Update() override;

  bool MightHaveChildren() override;

  size_t GetIndexOfChildWithName(ConstString name) override;

private:
  struct DictionaryItemDescriptor {
    lldb::addr_t key_ptr;
    lldb::addr_t val_ptr;
    lldb::ValueObjectSP valobj_sp;
  };

  ExecutionContextRef m_exe_ctx_ref;
  uint8_t m_ptr_size;
  lldb::ByteOrder m_order;
  D32 *m_data_32;
  D64 *m_data_64;
  CompilerType m_pair_type;
  std::vector<DictionaryItemDescriptor> m_children;
};
  
namespace Foundation1100 {
  class NSDictionaryMSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
  public:
    NSDictionaryMSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
    
    ~NSDictionaryMSyntheticFrontEnd() override;
    
    size_t CalculateNumChildren() override;
    
    lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
    
    bool Update() override;
    
    bool MightHaveChildren() override;
    
    size_t GetIndexOfChildWithName(ConstString name) override;
    
  private:
    struct DataDescriptor_32 {
      uint32_t _used : 26;
      uint32_t _kvo : 1;
      uint32_t _size;
      uint32_t _mutations;
      uint32_t _objs_addr;
      uint32_t _keys_addr;
    };
    
    struct DataDescriptor_64 {
      uint64_t _used : 58;
      uint32_t _kvo : 1;
      uint64_t _size;
      uint64_t _mutations;
      uint64_t _objs_addr;
      uint64_t _keys_addr;
    };
    
    struct DictionaryItemDescriptor {
      lldb::addr_t key_ptr;
      lldb::addr_t val_ptr;
      lldb::ValueObjectSP valobj_sp;
    };
    
    ExecutionContextRef m_exe_ctx_ref;
    uint8_t m_ptr_size;
    lldb::ByteOrder m_order;
    DataDescriptor_32 *m_data_32;
    DataDescriptor_64 *m_data_64;
    CompilerType m_pair_type;
    std::vector<DictionaryItemDescriptor> m_children;
  };
}
  
namespace Foundation1428 {
  struct DataDescriptor_32 {
    uint32_t _used : 26;
    uint32_t _kvo : 1;
    uint32_t _size;
    uint32_t _buffer;
    uint64_t GetSize() { return _size; }
  };
  
  struct DataDescriptor_64 {
    uint64_t _used : 58;
    uint32_t _kvo : 1;
    uint64_t _size;
    uint64_t _buffer;
    uint64_t GetSize() { return _size; }
  };
  
  
  
  using NSDictionaryMSyntheticFrontEnd =
    GenericNSDictionaryMSyntheticFrontEnd<DataDescriptor_32, DataDescriptor_64>;
}
  
namespace Foundation1437 {
  static const uint64_t NSDictionaryCapacities[] = {
      0, 3, 7, 13, 23, 41, 71, 127, 191, 251, 383, 631, 1087, 1723,
      2803, 4523, 7351, 11959, 19447, 31231, 50683, 81919, 132607,
      214519, 346607, 561109, 907759, 1468927, 2376191, 3845119,
      6221311, 10066421, 16287743, 26354171, 42641881, 68996069,
      111638519, 180634607, 292272623, 472907251
  };
  
  static const size_t NSDictionaryNumSizeBuckets = sizeof(NSDictionaryCapacities) / sizeof(uint64_t);
  
  struct DataDescriptor_32 {
    uint32_t _buffer;
    uint32_t _muts;
    uint32_t _used : 25;
    uint32_t _kvo : 1;
    uint32_t _szidx : 6;

    uint64_t GetSize() {
      return (_szidx) >= NSDictionaryNumSizeBuckets ?
          0 : NSDictionaryCapacities[_szidx];
    }
  };
  
  struct DataDescriptor_64 {
    uint64_t _buffer;
    uint32_t _muts;
    uint32_t _used : 25;
    uint32_t _kvo : 1;
    uint32_t _szidx : 6;

    uint64_t GetSize() {
      return (_szidx) >= NSDictionaryNumSizeBuckets ?
          0 : NSDictionaryCapacities[_szidx];
    }
  };
  
  using NSDictionaryMSyntheticFrontEnd =
    GenericNSDictionaryMSyntheticFrontEnd<DataDescriptor_32, DataDescriptor_64>;
  
  template <typename DD>
  uint64_t
  __NSDictionaryMSize_Impl(lldb_private::Process &process,
                           lldb::addr_t valobj_addr, Status &error) {
    const lldb::addr_t start_of_descriptor =
        valobj_addr + process.GetAddressByteSize();
    DD descriptor = DD();
    process.ReadMemory(start_of_descriptor, &descriptor, sizeof(descriptor),
                       error);
    if (error.Fail()) {
      return 0;
    }
    return descriptor._used;
  }
  
  uint64_t
  __NSDictionaryMSize(lldb_private::Process &process, lldb::addr_t valobj_addr,
               Status &error) {
    if (process.GetAddressByteSize() == 4) {
      return __NSDictionaryMSize_Impl<DataDescriptor_32>(process, valobj_addr,
                                                         error);
    } else {
      return __NSDictionaryMSize_Impl<DataDescriptor_64>(process, valobj_addr,
                                                         error);
    }
  }

}
} // namespace formatters
} // namespace lldb_private

template <bool name_entries>
bool lldb_private::formatters::NSDictionarySummaryProvider(
    ValueObject &valobj, Stream &stream, const TypeSummaryOptions &options) {
  static ConstString g_TypeHint("NSDictionary");
  ProcessSP process_sp = valobj.GetProcessSP();
  if (!process_sp)
    return false;

  ObjCLanguageRuntime *runtime = ObjCLanguageRuntime::Get(*process_sp);

  if (!runtime)
    return false;

  ObjCLanguageRuntime::ClassDescriptorSP descriptor(
      runtime->GetClassDescriptor(valobj));

  if (!descriptor || !descriptor->IsValid())
    return false;

  uint32_t ptr_size = process_sp->GetAddressByteSize();
  bool is_64bit = (ptr_size == 8);

  lldb::addr_t valobj_addr = valobj.GetValueAsUnsigned(0);

  if (!valobj_addr)
    return false;

  uint64_t value = 0;

  ConstString class_name(descriptor->GetClassName());

  static const ConstString g_DictionaryI("__NSDictionaryI");
  static const ConstString g_DictionaryM("__NSDictionaryM");
  static const ConstString g_DictionaryMLegacy("__NSDictionaryM_Legacy");
  static const ConstString g_DictionaryMImmutable("__NSDictionaryM_Immutable");
  static const ConstString g_Dictionary1("__NSSingleEntryDictionaryI");
  static const ConstString g_Dictionary0("__NSDictionary0");
  static const ConstString g_DictionaryCF("__NSCFDictionary");

  if (class_name.IsEmpty())
    return false;

  if (class_name == g_DictionaryI || class_name == g_DictionaryMImmutable) {
    Status error;
    value = process_sp->ReadUnsignedIntegerFromMemory(valobj_addr + ptr_size,
                                                      ptr_size, 0, error);
    if (error.Fail())
      return false;
    value &= (is_64bit ? ~0xFC00000000000000UL : ~0xFC000000U);
  } else if (class_name == g_DictionaryM || class_name == g_DictionaryMLegacy ||
             class_name == g_DictionaryCF) {
    AppleObjCRuntime *apple_runtime =
    llvm::dyn_cast_or_null<AppleObjCRuntime>(runtime);
    Status error;
    if (apple_runtime && apple_runtime->GetFoundationVersion() >= 1437) {
      value = Foundation1437::__NSDictionaryMSize(*process_sp, valobj_addr,
                                                  error);
    } else {
      value = process_sp->ReadUnsignedIntegerFromMemory(valobj_addr + ptr_size,
                                                        ptr_size, 0, error);
      value &= (is_64bit ? ~0xFC00000000000000UL : ~0xFC000000U);
    }
    if (error.Fail())
      return false;
  } else if (class_name == g_Dictionary1) {
    value = 1;
  } else if (class_name == g_Dictionary0) {
    value = 0;
  }
  else {
    auto &map(NSDictionary_Additionals::GetAdditionalSummaries());
    for (auto &candidate : map) {
      if (candidate.first && candidate.first->Match(class_name))
        return candidate.second(valobj, stream, options);
    }
    return false;
  }

  std::string prefix, suffix;
  if (Language *language = Language::FindPlugin(options.GetLanguage())) {
    if (!language->GetFormatterPrefixSuffix(valobj, g_TypeHint, prefix,
                                            suffix)) {
      prefix.clear();
      suffix.clear();
    }
  }

  stream.Printf("%s%" PRIu64 " %s%s%s", prefix.c_str(), value, "key/value pair",
                value == 1 ? "" : "s", suffix.c_str());
  return true;
}

SyntheticChildrenFrontEnd *
lldb_private::formatters::NSDictionarySyntheticFrontEndCreator(
    CXXSyntheticChildren *synth, lldb::ValueObjectSP valobj_sp) {
  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
  if (!process_sp)
    return nullptr;
  AppleObjCRuntime *runtime = llvm::dyn_cast_or_null<AppleObjCRuntime>(
      ObjCLanguageRuntime::Get(*process_sp));
  if (!runtime)
    return nullptr;

  CompilerType valobj_type(valobj_sp->GetCompilerType());
  Flags flags(valobj_type.GetTypeInfo());

  if (flags.IsClear(eTypeIsPointer)) {
    Status error;
    valobj_sp = valobj_sp->AddressOf(error);
    if (error.Fail() || !valobj_sp)
      return nullptr;
  }

  ObjCLanguageRuntime::ClassDescriptorSP descriptor(
      runtime->GetClassDescriptor(*valobj_sp));

  if (!descriptor || !descriptor->IsValid())
    return nullptr;

  ConstString class_name(descriptor->GetClassName());

  static const ConstString g_DictionaryI("__NSDictionaryI");
  static const ConstString g_DictionaryM("__NSDictionaryM");
  static const ConstString g_Dictionary1("__NSSingleEntryDictionaryI");
  static const ConstString g_DictionaryImmutable("__NSDictionaryM_Immutable");
  static const ConstString g_DictionaryMLegacy("__NSDictionaryM_Legacy");
  static const ConstString g_Dictionary0("__NSDictionary0");

  if (class_name.IsEmpty())
    return nullptr;

  if (class_name == g_DictionaryI) {
    return (new NSDictionaryISyntheticFrontEnd(valobj_sp));
  } else if (class_name == g_DictionaryM) {
    if (runtime->GetFoundationVersion() >= 1437) {
      return (new Foundation1437::NSDictionaryMSyntheticFrontEnd(valobj_sp));
    } else if (runtime->GetFoundationVersion() >= 1428) {
      return (new Foundation1428::NSDictionaryMSyntheticFrontEnd(valobj_sp));
    } else {
      return (new Foundation1100::NSDictionaryMSyntheticFrontEnd(valobj_sp));
    }
  } else if (class_name == g_DictionaryMLegacy) {
      return (new Foundation1100::NSDictionaryMSyntheticFrontEnd(valobj_sp));
  } else if (class_name == g_Dictionary1) {
    return (new NSDictionary1SyntheticFrontEnd(valobj_sp));
  } else {
    auto &map(NSDictionary_Additionals::GetAdditionalSynthetics());
    for (auto &candidate : map) {
      if (candidate.first && candidate.first->Match((class_name)))
        return candidate.second(synth, valobj_sp);
    }
  }

  return nullptr;
}

lldb_private::formatters::NSDictionaryISyntheticFrontEnd::
    NSDictionaryISyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
    : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(), m_ptr_size(8),
      m_order(lldb::eByteOrderInvalid), m_data_32(nullptr), m_data_64(nullptr),
      m_pair_type() {}

lldb_private::formatters::NSDictionaryISyntheticFrontEnd::
    ~NSDictionaryISyntheticFrontEnd() {
  delete m_data_32;
  m_data_32 = nullptr;
  delete m_data_64;
  m_data_64 = nullptr;
}

size_t lldb_private::formatters::NSDictionaryISyntheticFrontEnd::
    GetIndexOfChildWithName(ConstString name) {
  const char *item_name = name.GetCString();
  uint32_t idx = ExtractIndexFromString(item_name);
  if (idx < UINT32_MAX && idx >= CalculateNumChildren())
    return UINT32_MAX;
  return idx;
}

size_t lldb_private::formatters::NSDictionaryISyntheticFrontEnd::
    CalculateNumChildren() {
  if (!m_data_32 && !m_data_64)
    return 0;
  return (m_data_32 ? m_data_32->_used : m_data_64->_used);
}

bool lldb_private::formatters::NSDictionaryISyntheticFrontEnd::Update() {
  m_children.clear();
  delete m_data_32;
  m_data_32 = nullptr;
  delete m_data_64;
  m_data_64 = nullptr;
  m_ptr_size = 0;
  ValueObjectSP valobj_sp = m_backend.GetSP();
  if (!valobj_sp)
    return false;
  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
  Status error;
  error.Clear();
  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
  if (!process_sp)
    return false;
  m_ptr_size = process_sp->GetAddressByteSize();
  m_order = process_sp->GetByteOrder();
  uint64_t data_location = valobj_sp->GetValueAsUnsigned(0) + m_ptr_size;
  if (m_ptr_size == 4) {
    m_data_32 = new DataDescriptor_32();
    process_sp->ReadMemory(data_location, m_data_32, sizeof(DataDescriptor_32),
                           error);
  } else {
    m_data_64 = new DataDescriptor_64();
    process_sp->ReadMemory(data_location, m_data_64, sizeof(DataDescriptor_64),
                           error);
  }
  if (error.Fail())
    return false;
  m_data_ptr = data_location + m_ptr_size;
  return false;
}

bool lldb_private::formatters::NSDictionaryISyntheticFrontEnd::
    MightHaveChildren() {
  return true;
}

lldb::ValueObjectSP
lldb_private::formatters::NSDictionaryISyntheticFrontEnd::GetChildAtIndex(
    size_t idx) {
  uint32_t num_children = CalculateNumChildren();

  if (idx >= num_children)
    return lldb::ValueObjectSP();

  if (m_children.empty()) {
    // do the scan phase
    lldb::addr_t key_at_idx = 0, val_at_idx = 0;

    uint32_t tries = 0;
    uint32_t test_idx = 0;

    while (tries < num_children) {
      key_at_idx = m_data_ptr + (2 * test_idx * m_ptr_size);
      val_at_idx = key_at_idx + m_ptr_size;
      ProcessSP process_sp = m_exe_ctx_ref.GetProcessSP();
      if (!process_sp)
        return lldb::ValueObjectSP();
      Status error;
      key_at_idx = process_sp->ReadPointerFromMemory(key_at_idx, error);
      if (error.Fail())
        return lldb::ValueObjectSP();
      val_at_idx = process_sp->ReadPointerFromMemory(val_at_idx, error);
      if (error.Fail())
        return lldb::ValueObjectSP();

      test_idx++;

      if (!key_at_idx || !val_at_idx)
        continue;
      tries++;

      DictionaryItemDescriptor descriptor = {key_at_idx, val_at_idx,
                                             lldb::ValueObjectSP()};

      m_children.push_back(descriptor);
    }
  }

  if (idx >= m_children.size()) // should never happen
    return lldb::ValueObjectSP();

  DictionaryItemDescriptor &dict_item = m_children[idx];
  if (!dict_item.valobj_sp) {
    if (!m_pair_type.IsValid()) {
      TargetSP target_sp(m_backend.GetTargetSP());
      if (!target_sp)
        return ValueObjectSP();
      m_pair_type = GetLLDBNSPairType(target_sp);
    }
    if (!m_pair_type.IsValid())
      return ValueObjectSP();

    DataBufferSP buffer_sp(new DataBufferHeap(2 * m_ptr_size, 0));

    if (m_ptr_size == 8) {
      uint64_t *data_ptr = (uint64_t *)buffer_sp->GetBytes();
      *data_ptr = dict_item.key_ptr;
      *(data_ptr + 1) = dict_item.val_ptr;
    } else {
      uint32_t *data_ptr = (uint32_t *)buffer_sp->GetBytes();
      *data_ptr = dict_item.key_ptr;
      *(data_ptr + 1) = dict_item.val_ptr;
    }

    StreamString idx_name;
    idx_name.Printf("[%" PRIu64 "]", (uint64_t)idx);
    DataExtractor data(buffer_sp, m_order, m_ptr_size);
    dict_item.valobj_sp = CreateValueObjectFromData(idx_name.GetString(), data,
                                                    m_exe_ctx_ref, m_pair_type);
  }
  return dict_item.valobj_sp;
}

lldb_private::formatters::NSDictionary1SyntheticFrontEnd::
    NSDictionary1SyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
    : SyntheticChildrenFrontEnd(*valobj_sp.get()), m_pair(nullptr) {}

size_t lldb_private::formatters::NSDictionary1SyntheticFrontEnd::
    GetIndexOfChildWithName(ConstString name) {
  static const ConstString g_zero("[0]");
  return name == g_zero ? 0 : UINT32_MAX;
}

size_t lldb_private::formatters::NSDictionary1SyntheticFrontEnd::
    CalculateNumChildren() {
  return 1;
}

bool lldb_private::formatters::NSDictionary1SyntheticFrontEnd::Update() {
  m_pair.reset();
  return false;
}

bool lldb_private::formatters::NSDictionary1SyntheticFrontEnd::
    MightHaveChildren() {
  return true;
}

lldb::ValueObjectSP
lldb_private::formatters::NSDictionary1SyntheticFrontEnd::GetChildAtIndex(
    size_t idx) {
  if (idx != 0)
    return lldb::ValueObjectSP();

  if (m_pair.get())
    return m_pair;

  auto process_sp(m_backend.GetProcessSP());
  if (!process_sp)
    return nullptr;

  auto ptr_size = process_sp->GetAddressByteSize();

  lldb::addr_t key_ptr =
      m_backend.GetValueAsUnsigned(LLDB_INVALID_ADDRESS) + ptr_size;
  lldb::addr_t value_ptr = key_ptr + ptr_size;

  Status error;

  lldb::addr_t value_at_idx = process_sp->ReadPointerFromMemory(key_ptr, error);
  if (error.Fail())
    return nullptr;
  lldb::addr_t key_at_idx = process_sp->ReadPointerFromMemory(value_ptr, error);
  if (error.Fail())
    return nullptr;

  auto pair_type =
      GetLLDBNSPairType(process_sp->GetTarget().shared_from_this());

  DataBufferSP buffer_sp(new DataBufferHeap(2 * ptr_size, 0));

  if (ptr_size == 8) {
    uint64_t *data_ptr = (uint64_t *)buffer_sp->GetBytes();
    *data_ptr = key_at_idx;
    *(data_ptr + 1) = value_at_idx;
  } else {
    uint32_t *data_ptr = (uint32_t *)buffer_sp->GetBytes();
    *data_ptr = key_at_idx;
    *(data_ptr + 1) = value_at_idx;
  }

  DataExtractor data(buffer_sp, process_sp->GetByteOrder(), ptr_size);
  m_pair = CreateValueObjectFromData(
      "[0]", data, m_backend.GetExecutionContextRef(), pair_type);

  return m_pair;
}

template <typename D32, typename D64>
lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<D32,D64>::
    GenericNSDictionaryMSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
    : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(), m_ptr_size(8),
      m_order(lldb::eByteOrderInvalid), m_data_32(nullptr), m_data_64(nullptr),
      m_pair_type() {}

template <typename D32, typename D64>
lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<D32,D64>::
    ~GenericNSDictionaryMSyntheticFrontEnd() {
  delete m_data_32;
  m_data_32 = nullptr;
  delete m_data_64;
  m_data_64 = nullptr;
}

template <typename D32, typename D64>
size_t
lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<D32,D64>::    GetIndexOfChildWithName(ConstString name) {
  const char *item_name = name.GetCString();
  uint32_t idx = ExtractIndexFromString(item_name);
  if (idx < UINT32_MAX && idx >= CalculateNumChildren())
    return UINT32_MAX;
  return idx;
}

template <typename D32, typename D64>
size_t
lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<D32,D64>::CalculateNumChildren() {
  if (!m_data_32 && !m_data_64)
    return 0;
  return (m_data_32 ? m_data_32->_used : m_data_64->_used);
}

template <typename D32, typename D64>
bool
lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<D32,D64>::
  Update() {
  m_children.clear();
  ValueObjectSP valobj_sp = m_backend.GetSP();
  m_ptr_size = 0;
  delete m_data_32;
  m_data_32 = nullptr;
  delete m_data_64;
  m_data_64 = nullptr;
  if (!valobj_sp)
    return false;
  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
  Status error;
  error.Clear();
  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
  if (!process_sp)
    return false;
  m_ptr_size = process_sp->GetAddressByteSize();
  m_order = process_sp->GetByteOrder();
  uint64_t data_location = valobj_sp->GetValueAsUnsigned(0) + m_ptr_size;
  if (m_ptr_size == 4) {
    m_data_32 = new D32();
    process_sp->ReadMemory(data_location, m_data_32, sizeof(D32),
                           error);
  } else {
    m_data_64 = new D64();
    process_sp->ReadMemory(data_location, m_data_64, sizeof(D64),
                           error);
  }
  if (error.Fail())
    return false;
  return false;
}

template <typename D32, typename D64>
bool
lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<D32,D64>::
    MightHaveChildren() {
  return true;
}

template <typename D32, typename D64>
lldb::ValueObjectSP
lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<D32,D64>::
    GetChildAtIndex(
    size_t idx) {
  lldb::addr_t m_keys_ptr;
  lldb::addr_t m_values_ptr;
  if (m_data_32) {
    uint32_t size = m_data_32->GetSize();
    m_keys_ptr = m_data_32->_buffer;
    m_values_ptr = m_data_32->_buffer + (m_ptr_size * size);
  } else {
    uint32_t size = m_data_64->GetSize();
    m_keys_ptr = m_data_64->_buffer;
    m_values_ptr = m_data_64->_buffer + (m_ptr_size * size);
  }

  uint32_t num_children = CalculateNumChildren();

  if (idx >= num_children)
    return lldb::ValueObjectSP();

  if (m_children.empty()) {
    // do the scan phase
    lldb::addr_t key_at_idx = 0, val_at_idx = 0;

    uint32_t tries = 0;
    uint32_t test_idx = 0;

    while (tries < num_children) {
      key_at_idx = m_keys_ptr + (test_idx * m_ptr_size);
      val_at_idx = m_values_ptr + (test_idx * m_ptr_size);
      ;
      ProcessSP process_sp = m_exe_ctx_ref.GetProcessSP();
      if (!process_sp)
        return lldb::ValueObjectSP();
      Status error;
      key_at_idx = process_sp->ReadPointerFromMemory(key_at_idx, error);
      if (error.Fail())
        return lldb::ValueObjectSP();
      val_at_idx = process_sp->ReadPointerFromMemory(val_at_idx, error);
      if (error.Fail())
        return lldb::ValueObjectSP();

      test_idx++;

      if (!key_at_idx || !val_at_idx)
        continue;
      tries++;

      DictionaryItemDescriptor descriptor = {key_at_idx, val_at_idx,
                                             lldb::ValueObjectSP()};

      m_children.push_back(descriptor);
    }
  }

  if (idx >= m_children.size()) // should never happen
    return lldb::ValueObjectSP();

  DictionaryItemDescriptor &dict_item = m_children[idx];
  if (!dict_item.valobj_sp) {
    if (!m_pair_type.IsValid()) {
      TargetSP target_sp(m_backend.GetTargetSP());
      if (!target_sp)
        return ValueObjectSP();
      m_pair_type = GetLLDBNSPairType(target_sp);
    }
    if (!m_pair_type.IsValid())
      return ValueObjectSP();

    DataBufferSP buffer_sp(new DataBufferHeap(2 * m_ptr_size, 0));

    if (m_ptr_size == 8) {
      uint64_t *data_ptr = (uint64_t *)buffer_sp->GetBytes();
      *data_ptr = dict_item.key_ptr;
      *(data_ptr + 1) = dict_item.val_ptr;
    } else {
      uint32_t *data_ptr = (uint32_t *)buffer_sp->GetBytes();
      *data_ptr = dict_item.key_ptr;
      *(data_ptr + 1) = dict_item.val_ptr;
    }

    StreamString idx_name;
    idx_name.Printf("[%" PRIu64 "]", (uint64_t)idx);
    DataExtractor data(buffer_sp, m_order, m_ptr_size);
    dict_item.valobj_sp = CreateValueObjectFromData(idx_name.GetString(), data,
                                                    m_exe_ctx_ref, m_pair_type);
  }
  return dict_item.valobj_sp;
}


lldb_private::formatters::Foundation1100::
  NSDictionaryMSyntheticFrontEnd::
    NSDictionaryMSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
    : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(), m_ptr_size(8),
      m_order(lldb::eByteOrderInvalid), m_data_32(nullptr), m_data_64(nullptr),
      m_pair_type() {}

lldb_private::formatters::Foundation1100::
  NSDictionaryMSyntheticFrontEnd::~NSDictionaryMSyntheticFrontEnd() {
  delete m_data_32;
  m_data_32 = nullptr;
  delete m_data_64;
  m_data_64 = nullptr;
}

size_t
lldb_private::formatters::Foundation1100::
  NSDictionaryMSyntheticFrontEnd::GetIndexOfChildWithName(ConstString name) {
  const char *item_name = name.GetCString();
  uint32_t idx = ExtractIndexFromString(item_name);
  if (idx < UINT32_MAX && idx >= CalculateNumChildren())
    return UINT32_MAX;
  return idx;
}

size_t
lldb_private::formatters::Foundation1100::
  NSDictionaryMSyntheticFrontEnd::CalculateNumChildren() {
  if (!m_data_32 && !m_data_64)
    return 0;
  return (m_data_32 ? m_data_32->_used : m_data_64->_used);
}

bool
lldb_private::formatters::Foundation1100::
  NSDictionaryMSyntheticFrontEnd::Update() {
  m_children.clear();
  ValueObjectSP valobj_sp = m_backend.GetSP();
  m_ptr_size = 0;
  delete m_data_32;
  m_data_32 = nullptr;
  delete m_data_64;
  m_data_64 = nullptr;
  if (!valobj_sp)
    return false;
  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
  Status error;
  error.Clear();
  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
  if (!process_sp)
    return false;
  m_ptr_size = process_sp->GetAddressByteSize();
  m_order = process_sp->GetByteOrder();
  uint64_t data_location = valobj_sp->GetValueAsUnsigned(0) + m_ptr_size;
  if (m_ptr_size == 4) {
    m_data_32 = new DataDescriptor_32();
    process_sp->ReadMemory(data_location, m_data_32, sizeof(DataDescriptor_32),
                           error);
  } else {
    m_data_64 = new DataDescriptor_64();
    process_sp->ReadMemory(data_location, m_data_64, sizeof(DataDescriptor_64),
                           error);
  }
  if (error.Fail())
    return false;
  return false;
}

bool
lldb_private::formatters::Foundation1100::
  NSDictionaryMSyntheticFrontEnd::MightHaveChildren() {
  return true;
}

lldb::ValueObjectSP
lldb_private::formatters::Foundation1100::
  NSDictionaryMSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
  lldb::addr_t m_keys_ptr =
      (m_data_32 ? m_data_32->_keys_addr : m_data_64->_keys_addr);
  lldb::addr_t m_values_ptr =
      (m_data_32 ? m_data_32->_objs_addr : m_data_64->_objs_addr);

  uint32_t num_children = CalculateNumChildren();

  if (idx >= num_children)
    return lldb::ValueObjectSP();

  if (m_children.empty()) {
    // do the scan phase
    lldb::addr_t key_at_idx = 0, val_at_idx = 0;

    uint32_t tries = 0;
    uint32_t test_idx = 0;

    while (tries < num_children) {
      key_at_idx = m_keys_ptr + (test_idx * m_ptr_size);
      val_at_idx = m_values_ptr + (test_idx * m_ptr_size);
      ;
      ProcessSP process_sp = m_exe_ctx_ref.GetProcessSP();
      if (!process_sp)
        return lldb::ValueObjectSP();
      Status error;
      key_at_idx = process_sp->ReadPointerFromMemory(key_at_idx, error);
      if (error.Fail())
        return lldb::ValueObjectSP();
      val_at_idx = process_sp->ReadPointerFromMemory(val_at_idx, error);
      if (error.Fail())
        return lldb::ValueObjectSP();

      test_idx++;

      if (!key_at_idx || !val_at_idx)
        continue;
      tries++;

      DictionaryItemDescriptor descriptor = {key_at_idx, val_at_idx,
                                             lldb::ValueObjectSP()};

      m_children.push_back(descriptor);
    }
  }

  if (idx >= m_children.size()) // should never happen
    return lldb::ValueObjectSP();

  DictionaryItemDescriptor &dict_item = m_children[idx];
  if (!dict_item.valobj_sp) {
    if (!m_pair_type.IsValid()) {
      TargetSP target_sp(m_backend.GetTargetSP());
      if (!target_sp)
        return ValueObjectSP();
      m_pair_type = GetLLDBNSPairType(target_sp);
    }
    if (!m_pair_type.IsValid())
      return ValueObjectSP();

    DataBufferSP buffer_sp(new DataBufferHeap(2 * m_ptr_size, 0));

    if (m_ptr_size == 8) {
      uint64_t *data_ptr = (uint64_t *)buffer_sp->GetBytes();
      *data_ptr = dict_item.key_ptr;
      *(data_ptr + 1) = dict_item.val_ptr;
    } else {
      uint32_t *data_ptr = (uint32_t *)buffer_sp->GetBytes();
      *data_ptr = dict_item.key_ptr;
      *(data_ptr + 1) = dict_item.val_ptr;
    }

    StreamString idx_name;
    idx_name.Printf("[%" PRIu64 "]", (uint64_t)idx);
    DataExtractor data(buffer_sp, m_order, m_ptr_size);
    dict_item.valobj_sp = CreateValueObjectFromData(idx_name.GetString(), data,
                                                    m_exe_ctx_ref, m_pair_type);
  }
  return dict_item.valobj_sp;
}

template bool lldb_private::formatters::NSDictionarySummaryProvider<true>(
    ValueObject &, Stream &, const TypeSummaryOptions &);

template bool lldb_private::formatters::NSDictionarySummaryProvider<false>(
    ValueObject &, Stream &, const TypeSummaryOptions &);