<rdar://problem/12493007>

Added a new API call to help efficiently determine if a SBValue could have children:

     bool
     SBValue::MightHaveChildren ();
     
This is inteneded to be used bui GUI programs that need to show if a SBValue needs a disclosure triangle when displaying a hierarchical type in a tree view without having to complete the type (by calling SBValue::GetNumChildren()) as completing the type is expensive.

llvm-svn: 166460

3 files changed, 46 insertions, 0 deletions

diff --git a/lldb/source/API/SBValue.cpp b/lldb/source/API/SBValue.cpp
index 318029fdc43..9e80310f045 100644
--- a/lldb/source/API/SBValue.cpp
+++ b/lldb/source/API/SBValue.cpp
@@ -1354,6 +1354,20 @@ SBValue::GetValueAsUnsigned(uint64_t fail_value)
     return fail_value;
 }
 
+bool
+SBValue::MightHaveChildren ()
+{
+    LogSP log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_API));
+    bool has_children = false;
+    lldb::ValueObjectSP value_sp(GetSP());
+    if (value_sp)
+        has_children = value_sp->MightHaveChildren();
+
+    if (log)
+        log->Printf ("SBValue(%p)::HasChildren() => %i", value_sp.get(), has_children);
+    return has_children;
+}
+
 uint32_t
 SBValue::GetNumChildren ()
 {
diff --git a/lldb/source/Core/ValueObject.cpp b/lldb/source/Core/ValueObject.cpp
index b5b55c9e24b..41c7dbe94fd 100644
--- a/lldb/source/Core/ValueObject.cpp
+++ b/lldb/source/Core/ValueObject.cpp
@@ -597,6 +597,30 @@ ValueObject::GetNumChildren ()
     }
     return m_children.GetChildrenCount();
 }
+
+bool
+ValueObject::MightHaveChildren()
+{
+    bool has_children;
+    clang_type_t clang_type = GetClangType();
+    if (clang_type)
+    {
+        const uint32_t type_info = ClangASTContext::GetTypeInfo (clang_type,
+                                                                 GetClangAST(),
+                                                                 NULL);
+        if (type_info & (ClangASTContext::eTypeHasChildren |
+                         ClangASTContext::eTypeIsPointer |
+                         ClangASTContext::eTypeIsReference))
+            has_children = true;
+    }
+    else
+    {
+        has_children = GetNumChildren () > 0;
+    }
+    return has_children;
+}
+
+// Should only be called by ValueObject::GetNumChildren()
 void
 ValueObject::SetNumChildren (uint32_t num_children)
 {
diff --git a/lldb/source/Core/ValueObjectSyntheticFilter.cpp b/lldb/source/Core/ValueObjectSyntheticFilter.cpp
index 284515ab592..fe8e90cf181 100644
--- a/lldb/source/Core/ValueObjectSyntheticFilter.cpp
+++ b/lldb/source/Core/ValueObjectSyntheticFilter.cpp
@@ -96,6 +96,14 @@ ValueObjectSynthetic::CalculateNumChildren()
     return (m_synthetic_children_count = m_synth_filter_ap->CalculateNumChildren());
 }
 
+bool
+ValueObjectSynthetic::MightHaveChildren()
+{
+    // TODO: make this more efficient by adding API calls to calculate this efficiently
+    return GetNumChildren () > 0;
+}
+
+
 clang::ASTContext *
 ValueObjectSynthetic::GetClangASTImpl ()
 {