2 files changed, 48 insertions, 3 deletions
diff --git a/lldb/source/Core/CXXFormatterFunctions.cpp b/lldb/source/Core/CXXFormatterFunctions.cpp
index 67f769805ea..bc205b194a8 100644
--- a/lldb/source/Core/CXXFormatterFunctions.cpp
+++ b/lldb/source/Core/CXXFormatterFunctions.cpp
@@ -773,6 +773,12 @@ lldb_private::formatters::NSArrayMSyntheticFrontEnd::Update()
     return false;
 }
 
+bool
+lldb_private::formatters::NSArrayMSyntheticFrontEnd::MightHaveChildren ()
+{
+    return CalculateNumChildren() > 0;
+}
+
 static uint32_t
 ExtractIndexFromString (const char* item_name)
 {
@@ -882,6 +888,12 @@ lldb_private::formatters::NSArrayISyntheticFrontEnd::Update()
     return false;
 }
 
+bool
+lldb_private::formatters::NSArrayISyntheticFrontEnd::MightHaveChildren ()
+{
+    return CalculateNumChildren() > 0;
+}
+
 lldb::ValueObjectSP
 lldb_private::formatters::NSArrayISyntheticFrontEnd::GetChildAtIndex (uint32_t idx)
 {
@@ -976,6 +988,12 @@ lldb_private::formatters::NSArrayCodeRunningSyntheticFrontEnd::Update()
     return false;
 }
 
+bool
+lldb_private::formatters::NSArrayCodeRunningSyntheticFrontEnd::MightHaveChildren ()
+{
+    return CalculateNumChildren() > 0;
+}
+
 uint32_t
 lldb_private::formatters::NSArrayCodeRunningSyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
 {
@@ -1067,6 +1085,12 @@ lldb_private::formatters::NSDictionaryCodeRunningSyntheticFrontEnd::Update()
     return false;
 }
 
+bool
+lldb_private::formatters::NSDictionaryCodeRunningSyntheticFrontEnd::MightHaveChildren ()
+{
+    return CalculateNumChildren() > 0;
+}
+
 uint32_t
 lldb_private::formatters::NSDictionaryCodeRunningSyntheticFrontEnd::GetIndexOfChildWithName (const ConstString &name)
 {
@@ -1159,6 +1183,12 @@ lldb_private::formatters::NSDictionaryISyntheticFrontEnd::Update()
     return false;
 }
 
+bool
+lldb_private::formatters::NSDictionaryISyntheticFrontEnd::MightHaveChildren ()
+{
+    return CalculateNumChildren() > 0;
+}
+
 lldb::ValueObjectSP
 lldb_private::formatters::NSDictionaryISyntheticFrontEnd::GetChildAtIndex (uint32_t idx)
 {
@@ -1300,6 +1330,12 @@ lldb_private::formatters::NSDictionaryMSyntheticFrontEnd::Update()
     return false;
 }
 
+bool
+lldb_private::formatters::NSDictionaryMSyntheticFrontEnd::MightHaveChildren ()
+{
+    return CalculateNumChildren() > 0;
+}
+
 lldb::ValueObjectSP
 lldb_private::formatters::NSDictionaryMSyntheticFrontEnd::GetChildAtIndex (uint32_t idx)
 {
diff --git a/lldb/source/Core/ValueObjectSyntheticFilter.cpp b/lldb/source/Core/ValueObjectSyntheticFilter.cpp
index fe8e90cf181..e19d90085be 100644
--- a/lldb/source/Core/ValueObjectSyntheticFilter.cpp
+++ b/lldb/source/Core/ValueObjectSyntheticFilter.cpp
@@ -45,6 +45,12 @@ public:
     }
     
     bool
+    MightHaveChildren ()
+    {
+        return true;
+    }
+    
+    bool
     Update()
     {
         return false;
@@ -58,7 +64,8 @@ ValueObjectSynthetic::ValueObjectSynthetic (ValueObject &parent, lldb::Synthetic
     m_children_byindex(),
     m_name_toindex(),
     m_synthetic_children_count(UINT32_MAX),
-    m_parent_type_name(parent.GetTypeName())
+    m_parent_type_name(parent.GetTypeName()),
+    m_might_have_children(eLazyBoolCalculate)
 {
 #ifdef LLDB_CONFIGURATION_DEBUG
     std::string new_name(parent.GetName().AsCString());
@@ -99,8 +106,9 @@ ValueObjectSynthetic::CalculateNumChildren()
 bool
 ValueObjectSynthetic::MightHaveChildren()
 {
-    // TODO: make this more efficient by adding API calls to calculate this efficiently
-    return GetNumChildren () > 0;
+    if (m_might_have_children == eLazyBoolCalculate)
+        m_might_have_children = (m_synth_filter_ap->MightHaveChildren() ? eLazyBoolYes : eLazyBoolNo);
+    return (m_might_have_children == eLazyBoolNo ? false : true);
 }
 
 
@@ -164,6 +172,7 @@ ValueObjectSynthetic::UpdateValue ()
         // that they need to come back to us asking for children
         m_children_count_valid = false;
         m_synthetic_children_count = UINT32_MAX;
+        m_might_have_children = eLazyBoolCalculate;
     }
     
     CopyParentData();