Change signature of the public rename_level0

This reflects betters how we expect it to be used, and remove some
unused code.
Not that the old version of the signature has to be kept as it is used
for rename_type.

Author: romainbrenguier

src/goto-symex/goto_symex_state.cpp

@@ -280,14 +280,12 @@ static void set_l2_indices(
   ssa_expr.set_level_2(level2.current_count(ssa_expr.get_identifier()));
 }
 
-void goto_symex_statet::rename_level0(exprt &expr, const namespacet &ns)
+exprt goto_symex_statet::rename_level0(exprt expr, const namespacet &ns)
 {
   // rename all the symbols with their last known value
   if(auto ssa = expr_try_dynamic_cast<ssa_exprt>(expr))
   {
-    set_l0_indices(level0, *ssa, source.thread_nr, ns);
-    rename(expr.type(), ssa->get_identifier(), ns, L0);
-    ssa->update_type();
+    return rename_level0(*ssa, ns);
   }
   else if(expr.id() == ID_symbol)
   {
@@ -296,16 +294,17 @@ void goto_symex_statet::rename_level0(exprt &expr, const namespacet &ns)
     {
       rename(expr.type(), to_symbol_expr(expr).get_identifier(), ns, L0);
 
-      return;
+      return expr;
     }
 
     expr = ssa_exprt(expr);
-    rename_level0(expr, ns);
+    return rename_level0(expr, ns);
   }
   else if(auto address_of_expr = expr_try_dynamic_cast<address_of_exprt>(expr))
   {
     rename_address(address_of_expr->object(), ns, L0);
     to_pointer_type(expr.type()).subtype() = address_of_expr->object().type();
+    return expr;
   }
   else
   {
@@ -317,9 +316,20 @@ void goto_symex_statet::rename_level0(exprt &expr, const namespacet &ns)
       rename_level0(op, ns);
 
     fix_type(expr);
+    return expr;
   }
 }
 
+ssa_exprt
+goto_symex_statet::rename_level0(const symbol_exprt &expr, const namespacet &ns)
+{
+  ssa_exprt ssa{expr};
+  set_l0_indices(level0, ssa, source.thread_nr, ns);
+  rename(ssa.type(), ssa.get_identifier(), ns, L0);
+  ssa.update_type();
+  return ssa;
+}
+
 void goto_symex_statet::rename_level1(exprt &expr, const namespacet &ns)
 {
   // rename all the symbols with their last known value
@@ -612,10 +622,9 @@ void goto_symex_statet::rename_address(
   const namespacet &ns,
   levelt level)
 {
+  PRECONDITION(level != L0);
   auto rename_expr = [&](exprt &e) {
-    if(level == L0)
-      rename_level0(e, ns);
-    else if(level == L1)
+    if(level == L1)
       rename_level1(e, ns);
     else
       rename_level2(e, ns);
@@ -718,8 +727,8 @@ void goto_symex_statet::rename(
 {
   auto rename_expr = [&](exprt &e) {
     if(level == L0)
-      rename_level0(e, ns);
-    else if(level == L1)
+      e = rename_level0(std::move(e), ns);
+    if(level == L1)
       rename_level1(e, ns);
     else
       rename_level2(e, ns);

src/goto-symex/goto_symex_state.h

@@ -71,7 +71,7 @@ class goto_symex_statet final
   enum levelt { L0=0, L1=1, L2=2 };
 
   // performs renaming _up to_ the given level
-  void rename_level0(exprt &expr, const namespacet &ns);
+  ssa_exprt rename_level0(const symbol_exprt &expr, const namespacet &ns);
   void rename_level1(exprt &expr, const namespacet &ns);
   void rename_level2(exprt &expr, const namespacet &ns);
   void rename(
@@ -92,6 +92,7 @@ class goto_symex_statet final
   void get_original_name(exprt &expr) const;
   void get_original_name(typet &type) const;
 protected:
+  exprt rename_level0(exprt expr, const namespacet &ns);
   void rename_address(exprt &expr, const namespacet &ns, levelt level);
 
   // this maps L1 names to (L2) types

src/goto-symex/symex_function_call.cpp

@@ -399,8 +399,7 @@ void goto_symext::locality(
       it++)
   {
     // get L0 name
-    ssa_exprt ssa(ns.lookup(*it).symbol_expr());
-    state.rename_level0(ssa, ns);
+    ssa_exprt ssa = state.rename_level0(ns.lookup(*it).symbol_expr(), ns);
     const irep_idt l0_name=ssa.get_identifier();
 
     // save old L1 name for popping the frame