Use irept instead of symbol_exprt in java_lambda_method_handlest

A java_lambda_method_handlest really is just a collection of identifiers - there
is no need to put them into a symbol_exprt, instead the identifier can directly
be used as the id of an irept. This reduces the memory footprint, but more
importantly avoids a warning of using a deprecated symbol_exprt constructor.
This warning is well placed, because those symbol_exprt would never have a type
set, which makes them invalid symbol_exprt anyway.

Author: tautschnig

jbmc/src/java_bytecode/java_bytecode_convert_method.cpp

@@ -316,11 +316,11 @@ optionalt<symbolt> java_bytecode_convert_methodt::get_lambda_method_symbol(
   const java_class_typet::java_lambda_method_handlest &lambda_method_handles,
   const size_t index)
 {
-  const symbol_exprt &lambda_method_handle = lambda_method_handles.at(index);
+  const irept &lambda_method_handle = lambda_method_handles.at(index);
   // If the lambda method handle has an unknown type, it does not refer to
-  // any symbol (it is a symbol expression with empty identifier)
-  if(!lambda_method_handle.get_identifier().empty())
-    return symbol_table.lookup_ref(lambda_method_handle.get_identifier());
+  // any symbol (it has an empty identifier)
+  if(!lambda_method_handle.id().empty())
+    return symbol_table.lookup_ref(lambda_method_handle.id());
   return {};
 }
 

jbmc/src/java_bytecode/java_types.h

@@ -171,19 +171,16 @@ class java_class_typet:public class_typet
     set(ID_final, is_final);
   }
 
-  typedef std::vector<symbol_exprt> java_lambda_method_handlest;
+  using java_lambda_method_handlest = irept::subt;
 
   const java_lambda_method_handlest &lambda_method_handles() const
   {
-    return (const java_lambda_method_handlest &)find(
-             ID_java_lambda_method_handles)
-      .get_sub();
+    return find(ID_java_lambda_method_handles).get_sub();
   }
 
   java_lambda_method_handlest &lambda_method_handles()
   {
-    return (java_lambda_method_handlest &)add(ID_java_lambda_method_handles)
-      .get_sub();
+    return add(ID_java_lambda_method_handles).get_sub();
   }
 
   void add_lambda_method_handle(const irep_idt &identifier)

jbmc/unit/java-testing-utils/require_type.cpp

@@ -527,9 +527,9 @@ require_type::require_lambda_method_handles(
       lambda_method_handles.end(),
       expected_identifiers.begin(),
       [](
-        const symbol_exprt &lambda_method_handle,
+        const irept &lambda_method_handle,
         const std::string &expected_identifier) { //NOLINT
-        return lambda_method_handle.get_identifier() == expected_identifier;
+        return lambda_method_handle.id() == expected_identifier;
       }));
   return lambda_method_handles;
 }