[Lldb-commits] [lldb] [lldb][DataFormatter] Simplify libc++ std::map::iterator formatter (PR #97713)

[Pavel Labath via lldb-commits]

================
@@ -456,3 +477,97 @@ lldb_private::formatters::LibcxxStdMapSyntheticFrontEndCreator(
     CXXSyntheticChildren *, lldb::ValueObjectSP valobj_sp) {
   return (valobj_sp ? new LibcxxStdMapSyntheticFrontEnd(valobj_sp) : nullptr);
 }
+
+lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::
+    LibCxxMapIteratorSyntheticFrontEnd(lldb::ValueObjectSP valobj_sp)
+    : SyntheticChildrenFrontEnd(*valobj_sp) {
+  if (valobj_sp)
+    Update();
+}
+
+lldb::ChildCacheState
+lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::Update() {
+  m_pair_sp.reset();
+
+  ValueObjectSP valobj_sp = m_backend.GetSP();
+  if (!valobj_sp)
+    return lldb::ChildCacheState::eRefetch;
+
+  TargetSP target_sp(valobj_sp->GetTargetSP());
+  if (!target_sp)
+    return lldb::ChildCacheState::eRefetch;
+
+  auto tree_iter_sp = valobj_sp->GetChildMemberWithName("__i_");
+  if (!tree_iter_sp)
+    return lldb::ChildCacheState::eRefetch;
+
+  auto node_pointer_type =
+      tree_iter_sp->GetCompilerType().GetDirectNestedTypeWithName(
+          "__node_pointer");
+  if (!node_pointer_type.IsValid())
+    return lldb::ChildCacheState::eRefetch;
+
+  auto iter_pointer_sp = tree_iter_sp->GetChildMemberWithName("__ptr_");
+  if (!iter_pointer_sp)
+    return lldb::ChildCacheState::eRefetch;
+
+  auto node_pointer_sp = iter_pointer_sp->Cast(node_pointer_type);
+  if (!node_pointer_sp)
+    return lldb::ChildCacheState::eRefetch;
+
+  Status err;
+  node_pointer_sp = node_pointer_sp->Dereference(err);
+  if (!node_pointer_sp || err.Fail())
+    return lldb::ChildCacheState::eRefetch;
+
+  auto key_value_sp = node_pointer_sp->GetChildMemberWithName("__value_");
+  if (!key_value_sp)
+    return lldb::ChildCacheState::eRefetch;
+
+  key_value_sp = key_value_sp->Clone(ConstString("name"));
+  if (key_value_sp->GetNumChildrenIgnoringErrors() == 1) {
+    auto child0_sp = key_value_sp->GetChildAtIndex(0);
+    if (child0_sp &&
+        (child0_sp->GetName() == "__cc_" || child0_sp->GetName() == "__cc"))
+      key_value_sp = child0_sp->Clone(ConstString("pair"));
+  }
+
+  m_pair_sp = key_value_sp;
+
+  return lldb::ChildCacheState::eRefetch;
+}
+
+llvm::Expected<uint32_t> lldb_private::formatters::
+    LibCxxMapIteratorSyntheticFrontEnd::CalculateNumChildren() {
+  return 2;
+}
+
+lldb::ValueObjectSP
+lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::GetChildAtIndex(
+    uint32_t idx) {
+  if (!m_pair_sp)
+    return nullptr;
+
+  return m_pair_sp->GetChildAtIndex(idx);
+}
+
+bool lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::
+    MightHaveChildren() {
+  return true;
+}
+
+size_t lldb_private::formatters::LibCxxMapIteratorSyntheticFrontEnd::
+    GetIndexOfChildWithName(ConstString name) {
+  if (name == "first")
----------------
labath wrote:

Since `GetChildAtIndex` is forwarding to m_pair_sp, could this do the same as well?

https://github.com/llvm/llvm-project/pull/97713