Free the strong reference to a lldb::SBDebugger that the script interpreter was holding onto in the "lldb.debugger" global variable.

llvm-svn: 207292

lldb/include/lldb/Interpreter/ScriptInterpreter.h

@@ -414,6 +414,12 @@ public:
         return false;
     }
     
+    virtual void
+    Clear ()
+    {
+        // Clean up any ref counts to SBObjects that might be in global variables
+    }
+    
     virtual size_t
     CalculateNumChildren (const lldb::ScriptInterpreterObjectSP& implementor)
     {

lldb/include/lldb/Interpreter/ScriptInterpreterPython.h

@@ -170,6 +170,9 @@ public:
                         lldb::ScriptInterpreterObjectSP& callee_wrapper_sp,
                         std::string& retval);
     
+    virtual void
+    Clear ();
+
     virtual bool
     GetDocumentationForItem (const char* item, std::string& dest);
     

lldb/source/Interpreter/CommandInterpreter.cpp

@@ -355,6 +355,9 @@ void
 CommandInterpreter::Clear()
 {
     m_command_io_handler_sp.reset();
+    
+    if (m_script_interpreter_ap)
+        m_script_interpreter_ap->Clear();
 }
 
 const char *

lldb/source/Interpreter/ScriptInterpreterPython.cpp

@@ -1779,6 +1779,17 @@ ScriptInterpreterPython::GetScriptedSummary (const char *python_function_name,
     
 }
 
+void
+ScriptInterpreterPython::Clear ()
+{
+    // Release any global variables that might have strong references to
+    // LLDB objects when clearing the python script interpreter.
+    Locker locker(this,
+                  ScriptInterpreterPython::Locker::AcquireLock,
+                  ScriptInterpreterPython::Locker::FreeAcquiredLock);
+    PyRun_SimpleString("lldb.debugger = None; lldb.target = None; lldb.process = None; lldb.thread = None; lldb.frame = None");
+}
+
 bool
 ScriptInterpreterPython::BreakpointCallbackFunction 
 (