1 files changed, 1388 insertions, 0 deletions

diff --git a/contrib/llvm-project/lldb/source/Plugins/Language/ObjC/NSDictionary.cpp b/contrib/llvm-project/lldb/source/Plugins/Language/ObjC/NSDictionary.cpp
new file mode 100644
index 000000000000..ec6fd756394a
--- /dev/null
+++ b/contrib/llvm-project/lldb/source/Plugins/Language/ObjC/NSDictionary.cpp
@@ -0,0 +1,1388 @@
+//===-- NSDictionary.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 <mutex>
+
+#include "clang/AST/DeclCXX.h"
+
+#include "CFBasicHash.h"
+#include "NSDictionary.h"
+
+#include "Plugins/LanguageRuntime/ObjC/AppleObjCRuntime/AppleObjCRuntime.h"
+#include "Plugins/TypeSystem/Clang/TypeSystemClang.h"
+
+#include "lldb/Core/ValueObject.h"
+#include "lldb/Core/ValueObjectConstResult.h"
+#include "lldb/DataFormatters/FormattersHelpers.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().starts_with(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;
+  TypeSystemClangSP scratch_ts_sp =
+      ScratchTypeSystemClang::GetForTarget(*target_sp);
+
+  if (!scratch_ts_sp)
+    return compiler_type;
+
+  static constexpr llvm::StringLiteral g_lldb_autogen_nspair("__lldb_autogen_nspair");
+
+  compiler_type = scratch_ts_sp->GetTypeForIdentifier<clang::CXXRecordDecl>(g_lldb_autogen_nspair);
+
+  if (!compiler_type) {
+    compiler_type = scratch_ts_sp->CreateRecordType(
+        nullptr, OptionalClangModuleID(), lldb::eAccessPublic,
+        g_lldb_autogen_nspair, llvm::to_underlying(clang::TagTypeKind::Struct),
+        lldb::eLanguageTypeC);
+
+    if (compiler_type) {
+      TypeSystemClang::StartTagDeclarationDefinition(compiler_type);
+      CompilerType id_compiler_type =
+          scratch_ts_sp->GetBasicType(eBasicTypeObjCID);
+      TypeSystemClang::AddFieldToRecordType(
+          compiler_type, "key", id_compiler_type, lldb::eAccessPublic, 0);
+      TypeSystemClang::AddFieldToRecordType(
+          compiler_type, "value", id_compiler_type, lldb::eAccessPublic, 0);
+      TypeSystemClang::CompleteTagDeclarationDefinition(compiler_type);
+    }
+  }
+  return compiler_type;
+}
+
+namespace lldb_private {
+namespace formatters {
+class NSDictionaryISyntheticFrontEnd : public SyntheticChildrenFrontEnd {
+public:
+  NSDictionaryISyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
+
+  ~NSDictionaryISyntheticFrontEnd() override;
+
+  llvm::Expected<uint32_t> CalculateNumChildren() override;
+
+  lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
+
+  lldb::ChildCacheState 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 = 8;
+  lldb::ByteOrder m_order = lldb::eByteOrderInvalid;
+  DataDescriptor_32 *m_data_32 = nullptr;
+  DataDescriptor_64 *m_data_64 = nullptr;
+  lldb::addr_t m_data_ptr = LLDB_INVALID_ADDRESS;
+  CompilerType m_pair_type;
+  std::vector<DictionaryItemDescriptor> m_children;
+};
+
+class NSConstantDictionarySyntheticFrontEnd : public SyntheticChildrenFrontEnd {
+public:
+  NSConstantDictionarySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
+
+  llvm::Expected<uint32_t> CalculateNumChildren() override;
+
+  lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
+
+  lldb::ChildCacheState Update() override;
+
+  bool MightHaveChildren() override;
+
+  size_t GetIndexOfChildWithName(ConstString name) override;
+
+private:
+  ExecutionContextRef m_exe_ctx_ref;
+  CompilerType m_pair_type;
+  uint8_t m_ptr_size = 8;
+  lldb::ByteOrder m_order = lldb::eByteOrderInvalid;
+  unsigned int m_size = 0;
+  lldb::addr_t m_keys_ptr = LLDB_INVALID_ADDRESS;
+  lldb::addr_t m_objects_ptr = LLDB_INVALID_ADDRESS;
+
+  struct DictionaryItemDescriptor {
+    lldb::addr_t key_ptr;
+    lldb::addr_t val_ptr;
+    lldb::ValueObjectSP valobj_sp;
+  };
+
+  std::vector<DictionaryItemDescriptor> m_children;
+};
+
+class NSCFDictionarySyntheticFrontEnd : public SyntheticChildrenFrontEnd {
+public:
+  NSCFDictionarySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
+
+  llvm::Expected<uint32_t> CalculateNumChildren() override;
+
+  lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
+
+  lldb::ChildCacheState 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 = 8;
+  lldb::ByteOrder m_order = lldb::eByteOrderInvalid;
+
+  CFBasicHash m_hashtable;
+
+  CompilerType m_pair_type;
+  std::vector<DictionaryItemDescriptor> m_children;
+};
+
+class NSDictionary1SyntheticFrontEnd : public SyntheticChildrenFrontEnd {
+public:
+  NSDictionary1SyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
+
+  ~NSDictionary1SyntheticFrontEnd() override = default;
+
+  llvm::Expected<uint32_t> CalculateNumChildren() override;
+
+  lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
+
+  lldb::ChildCacheState 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;
+
+  llvm::Expected<uint32_t> CalculateNumChildren() override;
+
+  lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
+
+  lldb::ChildCacheState 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 = 8;
+  lldb::ByteOrder m_order = lldb::eByteOrderInvalid;
+  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;
+
+    llvm::Expected<uint32_t> CalculateNumChildren() override;
+
+    lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
+
+    lldb::ChildCacheState 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 = 8;
+    lldb::ByteOrder m_order = lldb::eByteOrderInvalid;
+    DataDescriptor_32 *m_data_32 = nullptr;
+    DataDescriptor_64 *m_data_64 = nullptr;
+    CompilerType m_pair_type;
+    std::vector<DictionaryItemDescriptor> m_children;
+  };
+}
+  
+namespace Foundation1428 {
+  namespace {
+    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);
+
+    namespace {
+    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];
+      }
+    };
+    } // namespace
+
+  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 constexpr llvm::StringLiteral 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->GetNonKVOClassDescriptor(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_DictionaryMFrozen("__NSFrozenDictionaryM");
+  static const ConstString g_Dictionary1("__NSSingleEntryDictionaryI");
+  static const ConstString g_Dictionary0("__NSDictionary0");
+  static const ConstString g_DictionaryCF("__CFDictionary");
+  static const ConstString g_DictionaryNSCF("__NSCFDictionary");
+  static const ConstString g_DictionaryCFRef("CFDictionaryRef");
+  static const ConstString g_ConstantDictionary("NSConstantDictionary");
+
+  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_ConstantDictionary) {
+    Status error;
+    value = process_sp->ReadUnsignedIntegerFromMemory(
+        valobj_addr + 2 * ptr_size, ptr_size, 0, error);
+    if (error.Fail())
+      return false;
+  } else if (class_name == g_DictionaryM || class_name == g_DictionaryMLegacy ||
+             class_name == g_DictionaryMFrozen) {
+    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 if (class_name == g_DictionaryCF || class_name == g_DictionaryNSCF ||
+             class_name == g_DictionaryCFRef) {
+    ExecutionContext exe_ctx(process_sp);
+    CFBasicHash cfbh;
+    if (!cfbh.Update(valobj_addr, exe_ctx))
+      return false;
+    value = cfbh.GetCount();
+  } 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;
+  }
+
+  llvm::StringRef prefix, suffix;
+  if (Language *language = Language::FindPlugin(options.GetLanguage()))
+    std::tie(prefix, suffix) = language->GetFormatterPrefixSuffix(g_TypeHint);
+
+  stream << prefix;
+  stream.Printf("%" PRIu64 " %s%s", value, "key/value pair",
+                value == 1 ? "" : "s");
+  stream << suffix;
+  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_DictionaryMFrozen("__NSFrozenDictionaryM");
+  static const ConstString g_DictionaryMLegacy("__NSDictionaryM_Legacy");
+  static const ConstString g_Dictionary0("__NSDictionary0");
+  static const ConstString g_DictionaryCF("__CFDictionary");
+  static const ConstString g_DictionaryNSCF("__NSCFDictionary");
+  static const ConstString g_DictionaryCFRef("CFDictionaryRef");
+  static const ConstString g_ConstantDictionary("NSConstantDictionary");
+
+  if (class_name.IsEmpty())
+    return nullptr;
+
+  if (class_name == g_DictionaryI) {
+    return (new NSDictionaryISyntheticFrontEnd(valobj_sp));
+  } else if (class_name == g_ConstantDictionary) {
+    return (new NSConstantDictionarySyntheticFrontEnd(valobj_sp));
+  } else if (class_name == g_DictionaryM || class_name == g_DictionaryMFrozen) {
+    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 if (class_name == g_DictionaryCF || class_name == g_DictionaryNSCF ||
+             class_name == g_DictionaryCFRef) {
+    return (new NSCFDictionarySyntheticFrontEnd(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_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 >= CalculateNumChildrenIgnoringErrors())
+    return UINT32_MAX;
+  return idx;
+}
+
+llvm::Expected<uint32_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);
+}
+
+lldb::ChildCacheState
+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 lldb::ChildCacheState::eRefetch;
+  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
+  Status error;
+  error.Clear();
+  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
+  if (!process_sp)
+    return lldb::ChildCacheState::eRefetch;
+  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 lldb::ChildCacheState::eRefetch;
+  m_data_ptr = data_location + m_ptr_size;
+  return lldb::ChildCacheState::eRefetch;
+}
+
+bool lldb_private::formatters::NSDictionaryISyntheticFrontEnd::
+    MightHaveChildren() {
+  return true;
+}
+
+lldb::ValueObjectSP
+lldb_private::formatters::NSDictionaryISyntheticFrontEnd::GetChildAtIndex(
+    uint32_t idx) {
+  uint32_t num_children = CalculateNumChildrenIgnoringErrors();
+
+  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();
+
+    WritableDataBufferSP 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::NSCFDictionarySyntheticFrontEnd::
+    NSCFDictionarySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
+    : SyntheticChildrenFrontEnd(*valobj_sp), m_exe_ctx_ref(), m_hashtable(),
+      m_pair_type() {}
+
+size_t lldb_private::formatters::NSCFDictionarySyntheticFrontEnd::
+    GetIndexOfChildWithName(ConstString name) {
+  const char *item_name = name.GetCString();
+  const uint32_t idx = ExtractIndexFromString(item_name);
+  if (idx < UINT32_MAX && idx >= CalculateNumChildrenIgnoringErrors())
+    return UINT32_MAX;
+  return idx;
+}
+
+llvm::Expected<uint32_t> lldb_private::formatters::
+    NSCFDictionarySyntheticFrontEnd::CalculateNumChildren() {
+  if (!m_hashtable.IsValid())
+    return 0;
+  return m_hashtable.GetCount();
+}
+
+lldb::ChildCacheState
+lldb_private::formatters::NSCFDictionarySyntheticFrontEnd::Update() {
+  m_children.clear();
+  ValueObjectSP valobj_sp = m_backend.GetSP();
+  m_ptr_size = 0;
+  if (!valobj_sp)
+    return lldb::ChildCacheState::eRefetch;
+  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
+
+  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
+  if (!process_sp)
+    return lldb::ChildCacheState::eRefetch;
+  m_ptr_size = process_sp->GetAddressByteSize();
+  m_order = process_sp->GetByteOrder();
+  return m_hashtable.Update(valobj_sp->GetValueAsUnsigned(0), m_exe_ctx_ref)
+             ? lldb::ChildCacheState::eReuse
+             : lldb::ChildCacheState::eRefetch;
+}
+
+bool lldb_private::formatters::NSCFDictionarySyntheticFrontEnd::
+    MightHaveChildren() {
+  return true;
+}
+
+lldb::ValueObjectSP
+lldb_private::formatters::NSCFDictionarySyntheticFrontEnd::GetChildAtIndex(
+    uint32_t idx) {
+  lldb::addr_t m_keys_ptr = m_hashtable.GetKeyPointer();
+  lldb::addr_t m_values_ptr = m_hashtable.GetValuePointer();
+
+  const uint32_t num_children = CalculateNumChildrenIgnoringErrors();
+
+  if (idx >= num_children)
+    return lldb::ValueObjectSP();
+
+  if (m_children.empty()) {
+    ProcessSP process_sp = m_exe_ctx_ref.GetProcessSP();
+    if (!process_sp)
+      return lldb::ValueObjectSP();
+
+    Status error;
+    lldb::addr_t key_at_idx = 0, val_at_idx = 0;
+
+    uint32_t tries = 0;
+    uint32_t test_idx = 0;
+
+    // Iterate over inferior memory, reading key/value pointers by shifting each
+    // cursor by test_index * m_ptr_size. Returns an empty ValueObject if a read
+    // fails, otherwise, continue until the number of tries matches the number
+    // of childen.
+    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);
+
+      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();
+
+    WritableDataBufferSP buffer_sp(new DataBufferHeap(2 * m_ptr_size, 0));
+
+    switch (m_ptr_size) {
+    case 0: // architecture has no clue - fail
+      return lldb::ValueObjectSP();
+    case 4: {
+      uint32_t *data_ptr = reinterpret_cast<uint32_t *>(buffer_sp->GetBytes());
+      *data_ptr = dict_item.key_ptr;
+      *(data_ptr + 1) = dict_item.val_ptr;
+    } break;
+    case 8: {
+      uint64_t *data_ptr = reinterpret_cast<uint64_t *>(buffer_sp->GetBytes());
+      *data_ptr = dict_item.key_ptr;
+      *(data_ptr + 1) = dict_item.val_ptr;
+    } break;
+    default:
+      lldbassert(false && "pointer size is not 4 nor 8");
+    }
+
+    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::NSConstantDictionarySyntheticFrontEnd::
+    NSConstantDictionarySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
+    : SyntheticChildrenFrontEnd(*valobj_sp) {}
+
+size_t lldb_private::formatters::NSConstantDictionarySyntheticFrontEnd::
+    GetIndexOfChildWithName(ConstString name) {
+  const char *item_name = name.GetCString();
+  uint32_t idx = ExtractIndexFromString(item_name);
+  if (idx < UINT32_MAX && idx >= CalculateNumChildrenIgnoringErrors())
+    return UINT32_MAX;
+  return idx;
+}
+
+llvm::Expected<uint32_t> lldb_private::formatters::
+    NSConstantDictionarySyntheticFrontEnd::CalculateNumChildren() {
+  return m_size;
+}
+
+lldb::ChildCacheState
+lldb_private::formatters::NSConstantDictionarySyntheticFrontEnd::Update() {
+  ValueObjectSP valobj_sp = m_backend.GetSP();
+  if (!valobj_sp)
+    return lldb::ChildCacheState::eRefetch;
+  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
+  Status error;
+  error.Clear();
+  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
+  if (!process_sp)
+    return lldb::ChildCacheState::eRefetch;
+  m_ptr_size = process_sp->GetAddressByteSize();
+  m_order = process_sp->GetByteOrder();
+  uint64_t valobj_addr = valobj_sp->GetValueAsUnsigned(0);
+  m_size = process_sp->ReadUnsignedIntegerFromMemory(
+      valobj_addr + 2 * m_ptr_size, m_ptr_size, 0, error);
+  if (error.Fail())
+    return lldb::ChildCacheState::eRefetch;
+  m_keys_ptr =
+      process_sp->ReadPointerFromMemory(valobj_addr + 3 * m_ptr_size, error);
+  if (error.Fail())
+    return lldb::ChildCacheState::eRefetch;
+  m_objects_ptr =
+      process_sp->ReadPointerFromMemory(valobj_addr + 4 * m_ptr_size, error);
+
+  return error.Success() ? lldb::ChildCacheState::eReuse
+                         : lldb::ChildCacheState::eRefetch;
+}
+
+bool lldb_private::formatters::NSConstantDictionarySyntheticFrontEnd::
+    MightHaveChildren() {
+  return true;
+}
+
+lldb::ValueObjectSP lldb_private::formatters::
+    NSConstantDictionarySyntheticFrontEnd::GetChildAtIndex(uint32_t idx) {
+  uint32_t num_children = CalculateNumChildrenIgnoringErrors();
+
+  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;
+    ProcessSP process_sp = m_exe_ctx_ref.GetProcessSP();
+    if (!process_sp)
+      return lldb::ValueObjectSP();
+
+    for (unsigned int child = 0; child < num_children; ++child) {
+      Status error;
+      key_at_idx = process_sp->ReadPointerFromMemory(
+          m_keys_ptr + child * m_ptr_size, error);
+      if (error.Fail())
+        return lldb::ValueObjectSP();
+      val_at_idx = process_sp->ReadPointerFromMemory(
+          m_objects_ptr + child * m_ptr_size, error);
+      if (error.Fail())
+        return lldb::ValueObjectSP();
+      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();
+
+    WritableDataBufferSP 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;
+}
+
+llvm::Expected<uint32_t> lldb_private::formatters::
+    NSDictionary1SyntheticFrontEnd::CalculateNumChildren() {
+  return 1;
+}
+
+lldb::ChildCacheState
+lldb_private::formatters::NSDictionary1SyntheticFrontEnd::Update() {
+  m_pair.reset();
+  return lldb::ChildCacheState::eRefetch;
+}
+
+bool lldb_private::formatters::NSDictionary1SyntheticFrontEnd::
+    MightHaveChildren() {
+  return true;
+}
+
+lldb::ValueObjectSP
+lldb_private::formatters::NSDictionary1SyntheticFrontEnd::GetChildAtIndex(
+    uint32_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());
+
+  WritableDataBufferSP 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_data_32(nullptr), m_data_64(nullptr), m_pair_type() {}
+
+template <typename D32, typename D64>
+lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<
+    D32, D64>::GenericNSDictionaryMSyntheticFrontEnd::
+    ~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 >= CalculateNumChildrenIgnoringErrors())
+    return UINT32_MAX;
+  return idx;
+}
+
+template <typename D32, typename D64>
+llvm::Expected<uint32_t>
+lldb_private::formatters::GenericNSDictionaryMSyntheticFrontEnd<
+    D32, D64>::CalculateNumChildren() {
+  if (!m_data_32 && !m_data_64)
+    return 0;
+  return (m_data_32 ? (uint32_t)m_data_32->_used : (uint32_t)m_data_64->_used);
+}
+
+template <typename D32, typename D64>
+lldb::ChildCacheState
+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 lldb::ChildCacheState::eRefetch;
+  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
+  Status error;
+  error.Clear();
+  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
+  if (!process_sp)
+    return lldb::ChildCacheState::eRefetch;
+  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);
+  }
+
+  return error.Success() ? lldb::ChildCacheState::eReuse
+                         : lldb::ChildCacheState::eRefetch;
+}
+
+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(uint32_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 = CalculateNumChildrenIgnoringErrors();
+
+  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();
+
+    WritableDataBufferSP 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_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 >= CalculateNumChildrenIgnoringErrors())
+    return UINT32_MAX;
+  return idx;
+}
+
+llvm::Expected<uint32_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);
+}
+
+lldb::ChildCacheState 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 lldb::ChildCacheState::eRefetch;
+  m_exe_ctx_ref = valobj_sp->GetExecutionContextRef();
+  Status error;
+  error.Clear();
+  lldb::ProcessSP process_sp(valobj_sp->GetProcessSP());
+  if (!process_sp)
+    return lldb::ChildCacheState::eRefetch;
+  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);
+  }
+
+  return error.Success() ? lldb::ChildCacheState::eReuse
+                         : lldb::ChildCacheState::eRefetch;
+}
+
+bool
+lldb_private::formatters::Foundation1100::
+  NSDictionaryMSyntheticFrontEnd::MightHaveChildren() {
+  return true;
+}
+
+lldb::ValueObjectSP
+lldb_private::formatters::Foundation1100::
+  NSDictionaryMSyntheticFrontEnd::GetChildAtIndex(uint32_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 = CalculateNumChildrenIgnoringErrors();
+
+  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();
+
+    WritableDataBufferSP 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 &);