Make locality a static function

locality is only used in symex_function_call.cpp, it can be made static.
This simplifies the symex interface and is potentially more efficient.

Author: romainbrenguier

src/goto-symex/goto_symex.h

@@ -310,11 +310,6 @@ class goto_symext
     statet &,
     const exprt::operandst &arguments);
 
-  void locality(
-    const irep_idt &function_identifier,
-    statet &,
-    const goto_functionst::goto_functiont &);
-
   // exceptions
   void symex_throw(statet &);
   void symex_catch(statet &);

src/goto-symex/symex_function_call.cpp

@@ -18,6 +18,12 @@ Author: Daniel Kroening, kroening@kroening.com
 #include <util/exception_utils.h>
 #include <util/invariant.h>
 
+static void locality(
+  const irep_idt &function_identifier,
+  goto_symext::statet &state,
+  const goto_functionst::goto_functiont &goto_function,
+  const namespacet &ns);
+
 bool goto_symext::get_unwind_recursion(const irep_idt &, unsigned, unsigned)
 {
   return false;
@@ -300,7 +306,7 @@ void goto_symext::symex_function_call_code(
   framet &frame = state.new_frame();
 
   // preserve locality of local variables
-  locality(identifier, state, goto_function);
+  locality(identifier, state, goto_function, ns);
 
   // assign actuals to formal parameters
   parameter_assignments(identifier, goto_function, state, arguments);
@@ -378,10 +384,11 @@ void goto_symext::symex_end_of_function(statet &state)
 
 /// preserves locality of local variables of a given function by applying L1
 /// renaming to the local identifiers
-void goto_symext::locality(
+static void locality(
   const irep_idt &function_identifier,
-  statet &state,
-  const goto_functionst::goto_functiont &goto_function)
+  goto_symext::statet &state,
+  const goto_functionst::goto_functiont &goto_function,
+  const namespacet &ns)
 {
   unsigned &frame_nr=
     state.threads[state.source.thread_nr].function_frame[function_identifier];