[Cherry-pick into next] Surface errors in GetNumChildren.

lldb/source/Plugins/Language/Swift/FoundationValueTypes.cpp

@@ -131,12 +131,12 @@ bool lldb_private::formatters::swift::IndexPath_SummaryProvider(
     stream.PutCString("2 indices");
   else if (value == g_array)
   {
-    if (underlying_enum_sp->GetNumChildren() != 1) 
+    if (underlying_enum_sp->GetNumChildrenIgnoringErrors() != 1)
       return false;
 
     underlying_enum_sp = underlying_enum_sp->GetChildAtIndex(0, true)
        ->GetQualifiedRepresentationIfAvailable(lldb::eDynamicDontRunTarget, true);
-    size_t num_children = underlying_enum_sp->GetNumChildren();
+    size_t num_children = underlying_enum_sp->GetNumChildrenIgnoringErrors();
     stream.Printf("%zu indices", num_children);
   }
   return true;
@@ -214,7 +214,7 @@ bool lldb_private::formatters::swift::UUID_SummaryProvider(
   if (!uuid_sp)
     return false;
 
-  if (uuid_sp->GetNumChildren() < 16)
+  if (uuid_sp->GetNumChildrenIgnoringErrors() < 16)
     return false;
 
   ValueObjectSP children[] = {
@@ -300,7 +300,7 @@ bool lldb_private::formatters::swift::Data_SummaryProvider(
     // Do nothing; count is already 0.
   } else if (representation_case == g_inline) {
     // Grab the associated value from `case inline(InlineData)`.
-    if (representation_enum_sp->GetNumChildren() != 1)
+    if (representation_enum_sp->GetNumChildrenIgnoringErrors() != 1)
       return false;
 
     ValueObjectSP inline_data_sp =
@@ -330,7 +330,7 @@ bool lldb_private::formatters::swift::Data_SummaryProvider(
     }
   } else if (representation_case == g_slice) {
     // Grab the associated value from `case slice(InlineSlice)`.
-    if (representation_enum_sp->GetNumChildren() != 1)
+    if (representation_enum_sp->GetNumChildrenIgnoringErrors() != 1)
       return false;
 
     ValueObjectSP slice_data_sp =
@@ -392,7 +392,7 @@ bool lldb_private::formatters::swift::Data_SummaryProvider(
     count = upperBound - lowerBound;
   } else if (representation_case == g_large) {
     // Grab the associated value from `case large(LargeSlice)`.
-    if (representation_enum_sp->GetNumChildren() != 1)
+    if (representation_enum_sp->GetNumChildrenIgnoringErrors() != 1)
       return false;
 
     ValueObjectSP large_data_sp =
@@ -521,7 +521,7 @@ bool lldb_private::formatters::swift::Decimal_SummaryProvider(
 
   // Mantissa is represented as a tuple of 8 UInt16.
   const uint8_t num_children = 8;
-  if (mantissa_sp->GetNumChildren() != num_children)
+  if (mantissa_sp->GetNumChildrenIgnoringErrors() != num_children)
     return false;
 
   std::vector<double> mantissa_elements;
@@ -570,13 +570,13 @@ class URLComponentsSyntheticChildrenFrontEnd
 
   ~URLComponentsSyntheticChildrenFrontEnd() override = default;
 
-  size_t CalculateNumChildren() override {
+  llvm::Expected<uint32_t> CalculateNumChildren() override {
     if (IsValid())
       return 9;
     return 0;
   }
 
-  lldb::ValueObjectSP GetChildAtIndex(size_t idx) override {
+  lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override {
     if (IsValid()) {
       switch (idx) {
 #define COMPONENT(Name, PrettyName, ID)                                        \

lldb/source/Plugins/Language/Swift/ObjCRuntimeSyntheticProvider.cpp

@@ -34,9 +34,10 @@ size_t ObjCRuntimeSyntheticProvider::FrontEnd::GetNumBases() {
   return m_provider->m_descriptor_sp->GetSuperclass().get() ? 1 : 0;
 }
 
-size_t ObjCRuntimeSyntheticProvider::FrontEnd::CalculateNumChildren() {
-  size_t ivars = m_provider->GetNumIVars();
-  size_t bases = GetNumBases();
+llvm::Expected<uint32_t>
+ObjCRuntimeSyntheticProvider::FrontEnd::CalculateNumChildren() {
+  uint32_t ivars = m_provider->GetNumIVars();
+  uint32_t bases = GetNumBases();
   return bases + ivars;
 }
 
@@ -59,9 +60,9 @@ ObjCRuntimeSyntheticProvider::FrontEnd::FrontEnd(
       m_root_sp(::GetSuitableRootObject(backend.GetSP())) {}
 
 lldb::ValueObjectSP
-ObjCRuntimeSyntheticProvider::FrontEnd::GetChildAtIndex(size_t idx) {
+ObjCRuntimeSyntheticProvider::FrontEnd::GetChildAtIndex(uint32_t idx) {
   lldb::ValueObjectSP child_sp(nullptr);
-  if (idx < CalculateNumChildren()) {
+  if (idx < CalculateNumChildrenIgnoringErrors()) {
     if (GetNumBases() == 1) {
       if (idx == 0) {
         do {
@@ -117,7 +118,7 @@ ObjCRuntimeSyntheticProvider::FrontEnd::GetChildAtIndex(size_t idx) {
 
 size_t ObjCRuntimeSyntheticProvider::FrontEnd::GetIndexOfChildWithName(
     ConstString name) {
-  for (size_t idx = 0; idx < CalculateNumChildren(); idx++) {
+  for (size_t idx = 0; idx < CalculateNumChildrenIgnoringErrors(); idx++) {
     const auto &ivar_info(m_provider->GetIVarAtIndex(idx));
     if (name == ivar_info.m_name)
       return idx + GetNumBases();

lldb/source/Plugins/Language/Swift/ObjCRuntimeSyntheticProvider.h

@@ -48,8 +48,8 @@ class ObjCRuntimeSyntheticProvider : public SyntheticChildren {
   public:
     FrontEnd(ObjCRuntimeSyntheticProvider *prv, ValueObject &backend);
 
-    size_t CalculateNumChildren() override;
-    lldb::ValueObjectSP GetChildAtIndex(size_t idx) override;
+    llvm::Expected<uint32_t> CalculateNumChildren() override;
+    lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override;
     lldb::ChildCacheState Update() override {
       return lldb::ChildCacheState::eRefetch;
     }

lldb/source/Plugins/Language/Swift/SwiftArray.cpp

@@ -120,7 +120,7 @@ bool SwiftArrayNativeBufferHandler::IsValid() {
 }
 
 size_t SwiftArrayBridgedBufferHandler::GetCount() {
-  return m_frontend->CalculateNumChildren();
+  return m_frontend->CalculateNumChildrenIgnoringErrors();
 }
 
 size_t SwiftArrayBridgedBufferHandler::GetCapacity() { return GetCount(); }
@@ -248,11 +248,11 @@ bool SwiftArraySliceBufferHandler::IsValid() {
 }
 
 size_t SwiftSyntheticFrontEndBufferHandler::GetCount() {
-  return m_frontend->CalculateNumChildren();
+  return m_frontend->CalculateNumChildrenIgnoringErrors();
 }
 
 size_t SwiftSyntheticFrontEndBufferHandler::GetCapacity() {
-  return m_frontend->CalculateNumChildren();
+  return m_frontend->CalculateNumChildrenIgnoringErrors();
 }
 
 lldb_private::CompilerType
@@ -471,14 +471,17 @@ lldb_private::formatters::swift::ArraySyntheticFrontEnd::ArraySyntheticFrontEnd(
     Update();
 }
 
-size_t lldb_private::formatters::swift::ArraySyntheticFrontEnd::
-    CalculateNumChildren() {
-  return m_array_buffer ? m_array_buffer->GetCount() : 0;
+llvm::Expected<uint32_t> lldb_private::formatters::swift::
+    ArraySyntheticFrontEnd::CalculateNumChildren() {
+  if (m_array_buffer)
+    return m_array_buffer->GetCount();
+  return llvm::make_error<llvm::StringError>("failed to update array data",
+                                             llvm::inconvertibleErrorCode());
 }
 
 lldb::ValueObjectSP
 lldb_private::formatters::swift::ArraySyntheticFrontEnd::GetChildAtIndex(
-    size_t idx) {
+    uint32_t idx) {
   if (!m_array_buffer)
     return ValueObjectSP();
 
@@ -511,7 +514,7 @@ size_t lldb_private::formatters::swift::ArraySyntheticFrontEnd::
     return UINT32_MAX;
   const char *item_name = name.GetCString();
   uint32_t idx = ExtractIndexFromString(item_name);
-  if (idx < UINT32_MAX && idx >= CalculateNumChildren())
+  if (idx < UINT32_MAX && idx >= CalculateNumChildrenIgnoringErrors())
     return UINT32_MAX;
   return idx;
 }

lldb/source/Plugins/Language/Swift/SwiftArray.h

@@ -164,8 +164,8 @@ bool Array_SummaryProvider(ValueObject &valobj, Stream &stream,
 class ArraySyntheticFrontEnd : public SyntheticChildrenFrontEnd {
 public:
   ArraySyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
-  size_t CalculateNumChildren() override;
-  lldb::ValueObjectSP GetChildAtIndex(size_t idx) 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;

lldb/source/Plugins/Language/Swift/SwiftFormatters.cpp

@@ -711,8 +711,8 @@ class EnumSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
 public:
   EnumSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
 
-  size_t CalculateNumChildren() override;
-  lldb::ValueObjectSP GetChildAtIndex(size_t idx) 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;
@@ -734,14 +734,14 @@ lldb_private::formatters::swift::EnumSyntheticFrontEnd::EnumSyntheticFrontEnd(
     Update();
 }
 
-size_t
+llvm::Expected<uint32_t>
 lldb_private::formatters::swift::EnumSyntheticFrontEnd::CalculateNumChildren() {
   return m_child_index != UINT32_MAX ? 1 : 0;
 }
 
 lldb::ValueObjectSP
 lldb_private::formatters::swift::EnumSyntheticFrontEnd::GetChildAtIndex(
-    size_t idx) {
+    uint32_t idx) {
   if (idx)
     return ValueObjectSP();
   if (m_child_index == UINT32_MAX)

lldb/source/Plugins/Language/Swift/SwiftHashedContainer.cpp

@@ -153,7 +153,7 @@ class CocoaHashedStorageHandler: public HashedStorageHandler {
     : m_cocoaObject_sp(cocoaObject_sp), m_frontend(frontend) {}
 
   virtual size_t GetCount() override {
-    return m_frontend->CalculateNumChildren();
+    return m_frontend->CalculateNumChildrenIgnoringErrors();
   }
 
   virtual CompilerType GetElementType() override {
@@ -702,13 +702,15 @@ HashedSyntheticChildrenFrontEnd::HashedSyntheticChildrenFrontEnd(
     m_buffer()
 {}
 
-size_t
+llvm::Expected<uint32_t>
 HashedSyntheticChildrenFrontEnd::CalculateNumChildren() {
-  return m_buffer ? m_buffer->GetCount() : 0;
+  if (m_buffer)
+    return m_buffer->GetCount();
+  return llvm::make_error<llvm::StringError>(
+      "failed to update hashed container", llvm::inconvertibleErrorCode());
 }
 
-ValueObjectSP
-HashedSyntheticChildrenFrontEnd::GetChildAtIndex(size_t idx) {
+ValueObjectSP HashedSyntheticChildrenFrontEnd::GetChildAtIndex(uint32_t idx) {
   if (!m_buffer)
     return ValueObjectSP();
 
@@ -737,7 +739,7 @@ HashedSyntheticChildrenFrontEnd::GetIndexOfChildWithName(ConstString name) {
     return UINT32_MAX;
   const char *item_name = name.GetCString();
   uint32_t idx = ExtractIndexFromString(item_name);
-  if (idx < UINT32_MAX && idx >= CalculateNumChildren())
+  if (idx < UINT32_MAX && idx >= CalculateNumChildrenIgnoringErrors())
     return UINT32_MAX;
   return idx;
 }

lldb/source/Plugins/Language/Swift/SwiftHashedContainer.h

@@ -134,8 +134,8 @@ class HashedSyntheticChildrenFrontEnd : public SyntheticChildrenFrontEnd {
   HashedSyntheticChildrenFrontEnd(const HashedCollectionConfig &config,
                                   lldb::ValueObjectSP valobj_sp);
 
-  size_t CalculateNumChildren() override;
-  lldb::ValueObjectSP GetChildAtIndex(size_t idx) 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;

lldb/source/Plugins/Language/Swift/SwiftLanguage.cpp

@@ -839,11 +839,9 @@ class ValueObjectWrapperSyntheticChildren : public SyntheticChildren {
     ValueObjectWrapperFrontEndProvider(ValueObject &backend)
         : SyntheticChildrenFrontEnd(backend) {}
 
-    size_t CalculateNumChildren() override {
-      return 1;
-    }
+    llvm::Expected<uint32_t> CalculateNumChildren() override { return 1; }
 
-    lldb::ValueObjectSP GetChildAtIndex(size_t idx) override {
+    lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override {
       return idx == 0 ? m_backend.GetSP() : nullptr;
     }
 

lldb/source/Plugins/Language/Swift/SwiftOptional.cpp

@@ -189,11 +189,9 @@ bool lldb_private::formatters::swift::SwiftOptionalSummaryProvider::
   if (!summary_sp) {
     if (lldb_private::DataVisualization::ShouldPrintAsOneLiner(*some))
       return false;
-    else
-      return (some->GetNumChildren() > 0);
-  } else
-    return (some->GetNumChildren() > 0) &&
-           (summary_sp->DoesPrintChildren(some));
+    return some->HasChildren();
+  }
+  return some->HasChildren() && summary_sp->DoesPrintChildren(some);
 }
 
 bool lldb_private::formatters::swift::SwiftOptionalSummaryProvider::
@@ -211,15 +209,15 @@ bool lldb_private::formatters::swift::SwiftOptionalSyntheticFrontEnd::IsEmpty()
   return (m_is_none == true || m_children == false || m_some == nullptr);
 }
 
-size_t lldb_private::formatters::swift::SwiftOptionalSyntheticFrontEnd::
-    CalculateNumChildren() {
+llvm::Expected<uint32_t> lldb_private::formatters::swift::
+    SwiftOptionalSyntheticFrontEnd::CalculateNumChildren() {
   if (IsEmpty())
     return 0;
   return m_some->GetNumChildren();
 }
 
 lldb::ValueObjectSP lldb_private::formatters::swift::
-    SwiftOptionalSyntheticFrontEnd::GetChildAtIndex(size_t idx) {
+    SwiftOptionalSyntheticFrontEnd::GetChildAtIndex(uint32_t idx) {
   if (IsEmpty())
     return nullptr;
   auto child = m_some->GetChildAtIndex(idx, true);
@@ -243,7 +241,7 @@ lldb::ChildCacheState lldb_private::formatters::swift::SwiftOptionalSyntheticFro
 
   m_is_none = false;
 
-  m_children = (m_some->GetNumChildren() > 0);
+  m_children = m_some->HasChildren();
 
   return ChildCacheState::eRefetch;
 }

lldb/source/Plugins/Language/Swift/SwiftOptional.h

@@ -82,8 +82,8 @@ class SwiftOptionalSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
 public:
   SwiftOptionalSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
 
-  size_t CalculateNumChildren() override;
-  lldb::ValueObjectSP GetChildAtIndex(size_t idx) 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;

lldb/source/Plugins/Language/Swift/SwiftUnsafeTypes.cpp

@@ -514,8 +514,8 @@ class UnsafeTypeSyntheticFrontEnd : public SwiftBasicTypeSyntheticFrontEnd {
 public:
   UnsafeTypeSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp);
 
-  size_t CalculateNumChildren() override;
-  lldb::ValueObjectSP GetChildAtIndex(size_t idx) 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;
@@ -547,15 +547,15 @@ lldb_private::formatters::swift::UnsafeTypeSyntheticFrontEnd::
     Update();
 }
 
-size_t lldb_private::formatters::swift::UnsafeTypeSyntheticFrontEnd::
-    CalculateNumChildren() {
+llvm::Expected<uint32_t> lldb_private::formatters::swift::
+    UnsafeTypeSyntheticFrontEnd::CalculateNumChildren() {
   return m_unsafe_ptr->GetCount();
 }
 
 lldb::ValueObjectSP
 lldb_private::formatters::swift::UnsafeTypeSyntheticFrontEnd::GetChildAtIndex(
-    size_t idx) {
-  const size_t num_children = CalculateNumChildren();
+    uint32_t idx) {
+  const uint32_t num_children = CalculateNumChildrenIgnoringErrors();
 
   if (idx >= num_children || idx >= m_children.size())
     return lldb::ValueObjectSP();
@@ -575,7 +575,7 @@ lldb_private::formatters::swift::UnsafeTypeSyntheticFrontEnd::Update() {
   if (m_unsafe_ptr->Update() == ChildCacheState::eRefetch)
     return ChildCacheState::eRefetch;
 
-  const size_t num_children = CalculateNumChildren();
+  const uint32_t num_children = CalculateNumChildrenIgnoringErrors();
   m_children = ::ExtractChildrenFromSwiftPointerValueObject(valobj_sp,
                                                           *m_unsafe_ptr.get());
   return m_children.size() == num_children ? ChildCacheState::eReuse