Index: include/lldb/API/SBCommandInterpreter.h
===================================================================
--- include/lldb/API/SBCommandInterpreter.h
+++ include/lldb/API/SBCommandInterpreter.h
@@ -139,7 +139,7 @@
     AddMultiwordCommand (const char* name, const char* help);
     
     lldb::SBCommand
-    AddCommand (const char* name, lldb::SBCommandPluginInterface *impl, const char* help);
+    AddCommand (const char* name, lldb::SBCommandPluginInterface *impl, const char* help, const char* syntax);
 
     void
     SourceInitFileInHomeDirectory (lldb::SBCommandReturnObject &result);
@@ -267,6 +267,7 @@
     virtual bool
     DoExecute (lldb::SBDebugger /*debugger*/,
                char** /*command*/,
+               size_t /*number of arguments*/,
                lldb::SBCommandReturnObject & /*result*/)
     {
         return false;
@@ -306,7 +307,7 @@
     AddMultiwordCommand(const char* name, const char* help = nullptr);
     
     lldb::SBCommand
-    AddCommand(const char* name, lldb::SBCommandPluginInterface* impl, const char* help = nullptr);
+    AddCommand(const char* name, lldb::SBCommandPluginInterface* impl, const char* help = nullptr, const char* syntax = nullptr);
     
 private:
     friend class SBDebugger;
Index: packages/Python/lldbsuite/test/functionalities/plugins/commands/plugin.cpp
===================================================================
--- packages/Python/lldbsuite/test/functionalities/plugins/commands/plugin.cpp
+++ packages/Python/lldbsuite/test/functionalities/plugins/commands/plugin.cpp
@@ -34,6 +34,7 @@
     virtual bool
     DoExecute (lldb::SBDebugger debugger,
                char** command,
+               size_t arg_count,
                lldb::SBCommandReturnObject &result)
     {
         if (command)
Index: source/API/SBCommandInterpreter.cpp
===================================================================
--- source/API/SBCommandInterpreter.cpp
+++ source/API/SBCommandInterpreter.cpp
@@ -149,11 +149,11 @@
         SBCommandReturnObject sb_return(&result);
         SBCommandInterpreter sb_interpreter(&m_interpreter);
         SBDebugger debugger_sb(m_interpreter.GetDebugger().shared_from_this());
-        bool ret = m_backend->DoExecute (debugger_sb,(char**)command.GetArgumentVector(), sb_return);
+        bool ret = m_backend->DoExecute (debugger_sb,(char**)command.GetArgumentVector(),command.GetArgumentCount(), sb_return);
         sb_return.Release();
         return ret;
     }
-    lldb::SBCommandPluginInterface* m_backend;
+    std::shared_ptr<lldb::SBCommandPluginInterface> m_backend;
 };
 
 SBCommandInterpreter::SBCommandInterpreter (CommandInterpreter *interpreter) :
@@ -595,10 +595,10 @@
 }
 
 lldb::SBCommand
-SBCommandInterpreter::AddCommand (const char* name, lldb::SBCommandPluginInterface* impl, const char* help)
+SBCommandInterpreter::AddCommand (const char* name, lldb::SBCommandPluginInterface* impl, const char* help, const char* syntax)
 {
     lldb::CommandObjectSP new_command_sp;
-    new_command_sp.reset(new CommandPluginInterfaceImplementation(*m_opaque_ptr,name, impl, help));
+    new_command_sp.reset(new CommandPluginInterfaceImplementation(*m_opaque_ptr,name, impl, help, syntax));
 
     if (new_command_sp && m_opaque_ptr->AddUserCommand(name, new_command_sp, true))
         return lldb::SBCommand(new_command_sp);
@@ -664,14 +664,14 @@
 }
 
 lldb::SBCommand
-SBCommand::AddCommand (const char* name, lldb::SBCommandPluginInterface *impl, const char* help)
+SBCommand::AddCommand (const char* name, lldb::SBCommandPluginInterface *impl, const char* help, const char* syntax)
 {
     if (!IsValid ())
         return lldb::SBCommand();
     if (!m_opaque_sp->IsMultiwordObject())
         return lldb::SBCommand();
     lldb::CommandObjectSP new_command_sp;
-    new_command_sp.reset(new CommandPluginInterfaceImplementation(m_opaque_sp->GetCommandInterpreter(),name,impl,help));
+    new_command_sp.reset(new CommandPluginInterfaceImplementation(m_opaque_sp->GetCommandInterpreter(),name,impl,help, syntax));
     if (new_command_sp && m_opaque_sp->LoadSubCommand(name,new_command_sp))
         return lldb::SBCommand(new_command_sp);
     return lldb::SBCommand();