[Lldb-commits] [lldb] [lldb] Upgrade `GetIndexOfChildWithName` to use `llvm::Expected` (PR #136693)

[Michael Buch via lldb-commits]

================
@@ -319,40 +319,41 @@ ValueObjectSynthetic::GetChildMemberWithName(llvm::StringRef name,
                                              bool can_create) {
   UpdateValueIfNeeded();
 
-  uint32_t index = GetIndexOfChildWithName(name);
+  auto index_or_err = GetIndexOfChildWithName(name);
 
-  if (index == UINT32_MAX)
+  if (!index_or_err)
     return lldb::ValueObjectSP();
 
-  return GetChildAtIndex(index, can_create);
+  return GetChildAtIndex(*index_or_err, can_create);
 }
 
-size_t ValueObjectSynthetic::GetIndexOfChildWithName(llvm::StringRef name_ref) {
+llvm::Expected<size_t>
+ValueObjectSynthetic::GetIndexOfChildWithName(llvm::StringRef name_ref) {
   UpdateValueIfNeeded();
 
   ConstString name(name_ref);
 
-  uint32_t found_index = UINT32_MAX;
-  bool did_find;
+  std::optional<uint32_t> found_index = std::nullopt;
   {
     std::lock_guard<std::mutex> guard(m_child_mutex);
     auto name_to_index = m_name_toindex.find(name.GetCString());
-    did_find = name_to_index != m_name_toindex.end();
-    if (did_find)
+    if (name_to_index != m_name_toindex.end())
       found_index = name_to_index->second;
   }
 
-  if (!did_find && m_synth_filter_up != nullptr) {
-    uint32_t index = m_synth_filter_up->GetIndexOfChildWithName(name);
-    if (index == UINT32_MAX)
-      return index;
+  if (!found_index.has_value() && m_synth_filter_up != nullptr) {
+    auto index_or_err = m_synth_filter_up->GetIndexOfChildWithName(name);
+    if (!index_or_err)
+      return llvm::createStringError("Cannot find index of child '%s'",
+                                     name.AsCString());
----------------
Michael137 wrote:

```suggestion
      return index_or_err.takeError();
```

https://github.com/llvm/llvm-project/pull/136693