Fixing a potential crasher where the new C++ synthetic children can return a NULL FrontEnd and cause LLDB to crash. This patch introduces a dummy front-end which the ValueObjectSynthetic can use lacking a real FrontEnd

llvm-svn: 163946

1 files changed, 35 insertions, 0 deletions

diff --git a/lldb/source/Core/ValueObjectSyntheticFilter.cpp b/lldb/source/Core/ValueObjectSyntheticFilter.cpp
index b5c29bc5e50..dc85fddbf0d 100644
--- a/lldb/source/Core/ValueObjectSyntheticFilter.cpp
+++ b/lldb/source/Core/ValueObjectSyntheticFilter.cpp
@@ -19,6 +19,39 @@
 
 using namespace lldb_private;
 
+class DummySyntheticFrontEnd : public SyntheticChildrenFrontEnd
+{
+public:
+    DummySyntheticFrontEnd(ValueObject &backend) :
+    SyntheticChildrenFrontEnd(backend)
+    {}
+
+    uint32_t
+    CalculateNumChildren()
+    {
+        return 0;
+    }
+    
+    lldb::ValueObjectSP
+    GetChildAtIndex (uint32_t idx)
+    {
+        return lldb::ValueObjectSP();
+    }
+    
+    uint32_t
+    GetIndexOfChildWithName (const ConstString &name)
+    {
+        return UINT32_MAX;
+    }
+    
+    bool
+    Update()
+    {
+        return false;
+    }
+
+};
+
 ValueObjectSynthetic::ValueObjectSynthetic (ValueObject &parent, lldb::SyntheticChildrenSP filter) :
     ValueObject(parent),
     m_synth_sp(filter),
@@ -34,6 +67,8 @@ ValueObjectSynthetic::ValueObjectSynthetic (ValueObject &parent, lldb::Synthetic
 #else
     SetName(parent.GetName());
 #endif
+    if (!m_synth_filter_ap.get())
+        m_synth_filter_ap.reset(new DummySyntheticFrontEnd(parent));
 }
 
 ValueObjectSynthetic::~ValueObjectSynthetic()