Compare access qualifiers in goto-diff

src/goto-diff/syntactic_diff.cpp

@@ -27,6 +27,46 @@ bool syntactic_difft::operator()()
       continue;
     }
 
+    // check access qualifiers
+    const symbolt *fun1 = goto_model1.symbol_table.lookup(it->first);
+    CHECK_RETURN(fun1 != nullptr);
+    const symbolt *fun2 = goto_model2.symbol_table.lookup(it->first);
+    CHECK_RETURN(fun2 != nullptr);
+    const irep_idt &class_name = fun1->type.get(ID_C_class);
+    bool function_access_changed =
+      fun1->type.get(ID_access) != fun2->type.get(ID_access);
+    bool class_access_changed = false;
+    bool field_access_changed = false;
+    if(!class_name.empty())
+    {
+      const symbolt *class1 = goto_model1.symbol_table.lookup(class_name);
+      CHECK_RETURN(class1 != nullptr);
+      const symbolt *class2 = goto_model2.symbol_table.lookup(class_name);
+      CHECK_RETURN(class2 != nullptr);
+      class_access_changed =
+        class1->type.get(ID_access) != class2->type.get(ID_access);
+      const class_typet &class_type1 = to_class_type(class1->type);
+      const class_typet &class_type2 = to_class_type(class2->type);
+      for(const auto &field1 : class_type1.components())
+      {
+        for(const auto &field2 : class_type2.components())
+        {
+          if(field1.get_name() == field2.get_name())
+          {
+            field_access_changed = field1.get_access() != field2.get_access();
+            break;
+          }
+        }
+        if(field_access_changed)
+          break;
+      }
+    }
+    if(function_access_changed || class_access_changed || field_access_changed)
+    {
+      modified_functions.insert(it->first);
+      continue;
+    }
+
     if(it->second.body.instructions.size() !=
        f_it->second.body.instructions.size())
     {