🍒 [lldb] upgrade GetIndexOfChildWithName to use llvm::Expected and ExtractIndexFromString to use std::optional

lldb/include/lldb/DataFormatters/FormattersHelpers.h

@@ -62,7 +62,7 @@ void AddFilter(TypeCategoryImpl::SharedPointer category_sp,
                llvm::StringRef type_name,
                ScriptedSyntheticChildren::Flags flags, bool regex = false);
 
-size_t ExtractIndexFromString(const char *item_name);
+std::optional<size_t> ExtractIndexFromString(const char *item_name);
 
 Address GetArrayAddressOrPointerValue(ValueObject &valobj);
 

lldb/include/lldb/DataFormatters/TypeSynthetic.h

@@ -51,7 +51,7 @@ class SyntheticChildrenFrontEnd {
 
   virtual lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) = 0;
 
-  virtual size_t GetIndexOfChildWithName(ConstString name) = 0;
+  virtual llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) = 0;
 
   /// This function is assumed to always succeed and if it fails, the front-end
   /// should know to deal with it in the correct way (most probably, by refusing
@@ -117,8 +117,9 @@ class SyntheticValueProviderFrontEnd : public SyntheticChildrenFrontEnd {
 
   lldb::ValueObjectSP GetChildAtIndex(uint32_t idx) override { return nullptr; }
 
-  size_t GetIndexOfChildWithName(ConstString name) override {
-    return UINT32_MAX;
+  llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override {
+    return llvm::createStringError("Type has no child named '%s'",
+                                   name.AsCString());
   }
 
   lldb::ChildCacheState Update() override {
@@ -343,7 +344,7 @@ class TypeFilterImpl : public SyntheticChildren {
 
     bool MightHaveChildren() override { return filter->GetCount() > 0; }
 
-    size_t GetIndexOfChildWithName(ConstString name) override;
+    llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override;
 
     typedef std::shared_ptr<SyntheticChildrenFrontEnd> SharedPointer;
 
@@ -442,7 +443,7 @@ class ScriptedSyntheticChildren : public SyntheticChildren {
 
     bool MightHaveChildren() override;
 
-    size_t GetIndexOfChildWithName(ConstString name) override;
+    llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override;
 
     lldb::ValueObjectSP GetSyntheticValue() override;
 

lldb/include/lldb/DataFormatters/VectorIterator.h

@@ -32,7 +32,7 @@ class VectorIteratorSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
 
   bool MightHaveChildren() override;
 
-  size_t GetIndexOfChildWithName(ConstString name) override;
+  llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override;
 
 private:
   ExecutionContextRef m_exe_ctx_ref;

lldb/include/lldb/Interpreter/ScriptInterpreter.h

@@ -385,10 +385,10 @@ class ScriptInterpreter : public PluginInterface {
     return lldb::ValueObjectSP();
   }
 
-  virtual int
+  virtual llvm::Expected<int>
   GetIndexOfChildWithName(const StructuredData::ObjectSP &implementor,
                           const char *child_name) {
-    return UINT32_MAX;
+    return llvm::createStringError("Type has no child named '%s'", child_name);
   }
 
   virtual bool

lldb/include/lldb/Symbol/CompilerType.h

@@ -481,9 +481,10 @@ class CompilerType {
 
   /// Lookup a child given a name. This function will match base class names and
   /// member member names in "clang_type" only, not descendants.
-  uint32_t GetIndexOfChildWithName(llvm::StringRef name,
-                                   ExecutionContext *exe_ctx,
-                                   bool omit_empty_base_classes) const;
+
+  llvm::Expected<uint32_t>
+  GetIndexOfChildWithName(llvm::StringRef name, ExecutionContext *exe_ctx,
+                          bool omit_empty_base_classes) const;
 
   /// Lookup a child member given a name. This function will match member names
   /// only and will descend into "clang_type" children in search for the first

lldb/include/lldb/Symbol/TypeSystem.h

@@ -409,10 +409,10 @@ class TypeSystem : public PluginInterface,
 
   // Lookup a child given a name. This function will match base class names and
   // member member names in "clang_type" only, not descendants.
-  virtual uint32_t GetIndexOfChildWithName(lldb::opaque_compiler_type_t type,
-                                           llvm::StringRef name,
-                                           ExecutionContext *exe_ctx,
-                                           bool omit_empty_base_classes) = 0;
+  virtual llvm::Expected<uint32_t>
+  GetIndexOfChildWithName(lldb::opaque_compiler_type_t type,
+                          llvm::StringRef name, ExecutionContext *exe_ctx,
+                          bool omit_empty_base_classes) = 0;
 
   // Lookup a child member given a name. This function will match member names
   // only and will descend into "clang_type" children in search for the first

lldb/include/lldb/ValueObject/ValueObject.h

@@ -502,7 +502,7 @@ class ValueObject {
   virtual lldb::ValueObjectSP GetChildMemberWithName(llvm::StringRef name,
                                                      bool can_create = true);
 
-  virtual size_t GetIndexOfChildWithName(llvm::StringRef name);
+  virtual llvm::Expected<size_t> GetIndexOfChildWithName(llvm::StringRef name);
 
   llvm::Expected<uint32_t> GetNumChildren(uint32_t max = UINT32_MAX);
   /// Like \c GetNumChildren but returns 0 on error.  You probably

lldb/include/lldb/ValueObject/ValueObjectRegister.h

@@ -52,7 +52,7 @@ class ValueObjectRegisterSet : public ValueObject {
   lldb::ValueObjectSP GetChildMemberWithName(llvm::StringRef name,
                                              bool can_create = true) override;
 
-  size_t GetIndexOfChildWithName(llvm::StringRef name) override;
+  llvm::Expected<size_t> GetIndexOfChildWithName(llvm::StringRef name) override;
 
 protected:
   bool UpdateValue() override;

lldb/include/lldb/ValueObject/ValueObjectSyntheticFilter.h

@@ -57,7 +57,7 @@ class ValueObjectSynthetic : public ValueObject {
   lldb::ValueObjectSP GetChildMemberWithName(llvm::StringRef name,
                                              bool can_create = true) override;
 
-  size_t GetIndexOfChildWithName(llvm::StringRef name) override;
+  llvm::Expected<size_t> GetIndexOfChildWithName(llvm::StringRef name) override;
 
   lldb::ValueObjectSP
   GetDynamicValue(lldb::DynamicValueType valueType) override;

lldb/source/API/SBValue.cpp

@@ -688,13 +688,15 @@ SBValue SBValue::GetChildAtIndex(uint32_t idx,
 uint32_t SBValue::GetIndexOfChildWithName(const char *name) {
   LLDB_INSTRUMENT_VA(this, name);
 
-  uint32_t idx = UINT32_MAX;
   ValueLocker locker;
   lldb::ValueObjectSP value_sp(GetSP(locker));
   if (value_sp) {
-    idx = value_sp->GetIndexOfChildWithName(name);
+    if (auto idx_or_err = value_sp->GetIndexOfChildWithName(name))
+      return *idx_or_err;
+    else
+      llvm::consumeError(idx_or_err.takeError());
   }
-  return idx;
+  return UINT32_MAX;
 }
 
 SBValue SBValue::GetChildMemberWithName(const char *name) {

lldb/source/DataFormatters/FormatterBytecode.cpp

@@ -9,6 +9,7 @@
 #include "FormatterBytecode.h"
 #include "lldb/Utility/LLDBLog.h"
 #include "lldb/ValueObject/ValueObject.h"
+#include "lldb/ValueObject/ValueObjectConstResult.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/DataExtractor.h"
 #include "llvm/Support/Format.h"
@@ -486,7 +487,10 @@ llvm::Error Interpret(std::vector<ControlStackElement> &control,
         TYPE_CHECK(Object, String);
         auto name = data.Pop<std::string>();
         POP_VALOBJ(valobj);
-        data.Push((uint64_t)valobj->GetIndexOfChildWithName(name));
+        if (auto index_or_err = valobj->GetIndexOfChildWithName(name))
+          data.Push((uint64_t)*index_or_err);
+        else
+          return index_or_err.takeError();
         break;
       }
       case sel_get_type: {

lldb/source/DataFormatters/FormattersHelpers.cpp

@@ -401,18 +401,17 @@ void lldb_private::formatters::AddFilter(
   category_sp->AddTypeFilter(type_name, match_type, filter_sp);
 }
 
-size_t lldb_private::formatters::ExtractIndexFromString(const char *item_name) {
+std::optional<size_t>
+lldb_private::formatters::ExtractIndexFromString(const char *item_name) {
   if (!item_name || !*item_name)
-    return UINT32_MAX;
+    return std::nullopt;
   if (*item_name != '[')
-    return UINT32_MAX;
+    return std::nullopt;
   item_name++;
   char *endptr = nullptr;
   unsigned long int idx = ::strtoul(item_name, &endptr, 0);
-  if (idx == 0 && endptr == item_name)
-    return UINT32_MAX;
-  if (idx == ULONG_MAX)
-    return UINT32_MAX;
+  if ((idx == 0 && endptr == item_name) || idx == ULONG_MAX)
+    return std::nullopt;
   return idx;
 }
 

lldb/source/DataFormatters/TypeSynthetic.cpp

@@ -49,7 +49,7 @@ bool TypeFilterImpl::SetExpressionPathAtIndex(size_t i,
   return true;
 }
 
-size_t
+llvm::Expected<size_t>
 TypeFilterImpl::FrontEnd::GetIndexOfChildWithName(ConstString name) {
   const char *name_cstr = name.GetCString();
   if (name_cstr) {
@@ -67,7 +67,8 @@ TypeFilterImpl::FrontEnd::GetIndexOfChildWithName(ConstString name) {
       }
     }
   }
-  return UINT32_MAX;
+  return llvm::createStringError("Type has no child named '%s'",
+                                 name.AsCString());
 }
 
 std::string TypeFilterImpl::GetDescription() {
@@ -218,10 +219,11 @@ bool ScriptedSyntheticChildren::FrontEnd::MightHaveChildren() {
   return m_interpreter->MightHaveChildrenSynthProviderInstance(m_wrapper_sp);
 }
 
-size_t ScriptedSyntheticChildren::FrontEnd::GetIndexOfChildWithName(
-    ConstString name) {
+llvm::Expected<size_t>
+ScriptedSyntheticChildren::FrontEnd::GetIndexOfChildWithName(ConstString name) {
   if (!m_wrapper_sp || m_interpreter == nullptr)
-    return UINT32_MAX;
+    return llvm::createStringError("Type has no child named '%s'",
+                                   name.AsCString());
   return m_interpreter->GetIndexOfChildWithName(m_wrapper_sp,
                                                 name.GetCString());
 }

lldb/source/DataFormatters/VectorType.cpp

@@ -271,11 +271,16 @@ class VectorTypeSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
 
   bool MightHaveChildren() override { return true; }
 
-  size_t GetIndexOfChildWithName(ConstString name) override {
-    const char *item_name = name.GetCString();
-    uint32_t idx = ExtractIndexFromString(item_name);
-    if (idx < UINT32_MAX && idx >= CalculateNumChildrenIgnoringErrors())
-      return UINT32_MAX;
+  llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override {
+    auto optional_idx = ExtractIndexFromString(name.AsCString());
+    if (!optional_idx) {
+      return llvm::createStringError("Type has no child named '%s'",
+                                     name.AsCString());
+    }
+    uint32_t idx = *optional_idx;
+    if (idx >= CalculateNumChildrenIgnoringErrors())
+      return llvm::createStringError("Type has no child named '%s'",
+                                     name.AsCString());
     return idx;
   }
 

lldb/source/Plugins/Language/CPlusPlus/BlockPointer.cpp

@@ -147,9 +147,10 @@ class BlockPointerSyntheticFrontEnd : public SyntheticChildrenFrontEnd {
   // maybe return false if the block pointer is, say, null
   bool MightHaveChildren() override { return true; }
 
-  size_t GetIndexOfChildWithName(ConstString name) override {
+  llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override {
     if (!m_block_struct_type.IsValid())
-      return UINT32_MAX;
+      return llvm::createStringError("Type has no child named '%s'",
+                                     name.AsCString());
 
     const bool omit_empty_base_classes = false;
     return m_block_struct_type.GetIndexOfChildWithName(
@@ -175,8 +176,17 @@ bool lldb_private::formatters::BlockPointerSummaryProvider(
 
   static const ConstString s_FuncPtr_name("__FuncPtr");
 
-  lldb::ValueObjectSP child_sp = synthetic_children->GetChildAtIndex(
-      synthetic_children->GetIndexOfChildWithName(s_FuncPtr_name));
+  auto index_or_err =
+      synthetic_children->GetIndexOfChildWithName(s_FuncPtr_name);
+
+  if (!index_or_err) {
+    LLDB_LOG_ERROR(GetLog(LLDBLog::DataFormatters), index_or_err.takeError(),
+                   "{0}");
+    return false;
+  }
+
+  lldb::ValueObjectSP child_sp =
+      synthetic_children->GetChildAtIndex(*index_or_err);
 
   if (!child_sp) {
     return false;

lldb/source/Plugins/Language/CPlusPlus/Coroutines.cpp

@@ -204,10 +204,12 @@ bool lldb_private::formatters::StdlibCoroutineHandleSyntheticFrontEnd::
   return true;
 }
 
-size_t StdlibCoroutineHandleSyntheticFrontEnd::GetIndexOfChildWithName(
+llvm::Expected<size_t>
+StdlibCoroutineHandleSyntheticFrontEnd::GetIndexOfChildWithName(
     ConstString name) {
   if (!m_resume_ptr_sp || !m_destroy_ptr_sp)
-    return UINT32_MAX;
+    return llvm::createStringError("Type has no child named '%s'",
+                                   name.AsCString());
 
   if (name == ConstString("resume"))
     return 0;
@@ -216,7 +218,8 @@ size_t StdlibCoroutineHandleSyntheticFrontEnd::GetIndexOfChildWithName(
   if (name == ConstString("promise_ptr") && m_promise_ptr_sp)
     return 2;
 
-  return UINT32_MAX;
+  return llvm::createStringError("Type has no child named '%s'",
+                                 name.AsCString());
 }
 
 SyntheticChildrenFrontEnd *

lldb/source/Plugins/Language/CPlusPlus/Coroutines.h

@@ -42,7 +42,7 @@ class StdlibCoroutineHandleSyntheticFrontEnd
 
   bool MightHaveChildren() override;
 
-  size_t GetIndexOfChildWithName(ConstString name) override;
+  llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override;
 
 private:
   lldb::ValueObjectSP m_resume_ptr_sp;

lldb/source/Plugins/Language/CPlusPlus/GenericBitset.cpp

@@ -28,8 +28,13 @@ class GenericBitsetFrontEnd : public SyntheticChildrenFrontEnd {
 
   GenericBitsetFrontEnd(ValueObject &valobj, StdLib stdlib);
 
-  size_t GetIndexOfChildWithName(ConstString name) override {
-    return formatters::ExtractIndexFromString(name.GetCString());
+  llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override {
+    auto optional_idx = formatters::ExtractIndexFromString(name.GetCString());
+    if (!optional_idx) {
+      return llvm::createStringError("Type has no child named '%s'",
+                                     name.AsCString());
+    }
+    return *optional_idx;
   }
 
   bool MightHaveChildren() override { return true; }

lldb/source/Plugins/Language/CPlusPlus/GenericOptional.cpp

@@ -36,8 +36,13 @@ class GenericOptionalFrontend : public SyntheticChildrenFrontEnd {
 
   GenericOptionalFrontend(ValueObject &valobj, StdLib stdlib);
 
-  size_t GetIndexOfChildWithName(ConstString name) override {
-    return formatters::ExtractIndexFromString(name.GetCString());
+  llvm::Expected<size_t> GetIndexOfChildWithName(ConstString name) override {
+    auto optional_idx = formatters::ExtractIndexFromString(name.GetCString());
+    if (!optional_idx) {
+      return llvm::createStringError("Type has no child named '%s'",
+                                     name.AsCString());
+    }
+    return *optional_idx;
   }
 
   bool MightHaveChildren() override { return true; }