diff --git a/jbmc/regression/jdiff/java-clinit-wrapper/new.jar b/jbmc/regression/jdiff/java-clinit-wrapper/new.jar
new file mode 100644
index 00000000000..e27225a80af
Binary files /dev/null and b/jbmc/regression/jdiff/java-clinit-wrapper/new.jar differ
diff --git a/jbmc/regression/jdiff/java-clinit-wrapper/old.jar b/jbmc/regression/jdiff/java-clinit-wrapper/old.jar
new file mode 100644
index 00000000000..892477ce008
Binary files /dev/null and b/jbmc/regression/jdiff/java-clinit-wrapper/old.jar differ
diff --git a/jbmc/regression/jdiff/java-clinit-wrapper/test.desc b/jbmc/regression/jdiff/java-clinit-wrapper/test.desc
new file mode 100644
index 00000000000..a4f9c4d1554
--- /dev/null
+++ b/jbmc/regression/jdiff/java-clinit-wrapper/test.desc
@@ -0,0 +1,8 @@
+CORE
+new.jar
+old.jar
+EXIT=0
+SIGNAL=0
+--
+java::java\.nio\.charset\.StandardCharsets::clinit_wrapper$
+java::org\.apache\.tika\.mime\.MediaType::clinit_wrapper$
diff --git a/jbmc/src/java_bytecode/java_bytecode_convert_class.cpp b/jbmc/src/java_bytecode/java_bytecode_convert_class.cpp
index dbc8054390c..46e220e6436 100644
--- a/jbmc/src/java_bytecode/java_bytecode_convert_class.cpp
+++ b/jbmc/src/java_bytecode/java_bytecode_convert_class.cpp
@@ -760,15 +760,12 @@ void java_bytecode_convert_classt::add_array_types(symbol_tablet &symbol_table)
 
     const irep_idt clone_name=
       id2string(symbol_type_identifier)+".clone:()Ljava/lang/Object;";
-    code_typet clone_type;
-    clone_type.return_type()=
-      java_reference_type(symbol_typet("java::java.lang.Object"));
     code_typet::parametert this_param;
     this_param.set_identifier(id2string(clone_name)+"::this");
     this_param.set_base_name("this");
     this_param.set_this();
     this_param.type()=java_reference_type(symbol_type);
-    clone_type.parameters().push_back(this_param);
+    code_typet clone_type({this_param}, java_lang_object_type());
 
     parameter_symbolt this_symbol;
     this_symbol.name=this_param.get_identifier();
diff --git a/jbmc/src/java_bytecode/java_entry_point.cpp b/jbmc/src/java_bytecode/java_entry_point.cpp
index 9181dc48026..1258ffae4c9 100644
--- a/jbmc/src/java_bytecode/java_entry_point.cpp
+++ b/jbmc/src/java_bytecode/java_entry_point.cpp
@@ -31,8 +31,7 @@ static void create_initialize(symbol_table_baset &symbol_table)
   initialize.base_name=INITIALIZE_FUNCTION;
   initialize.mode=ID_java;
 
-  code_typet type;
-  type.return_type()=empty_typet();
+  code_typet type({}, empty_typet());
   initialize.type=type;
 
   code_blockt init_code;
@@ -688,8 +687,7 @@ bool generate_java_start_function(
   // we just built and register it in the symbol table
   symbolt new_symbol;
 
-  code_typet main_type;
-  main_type.return_type()=empty_typet();
+  code_typet main_type({}, empty_typet());
 
   new_symbol.name=goto_functionst::entry_point();
   new_symbol.type.swap(main_type);
diff --git a/jbmc/src/java_bytecode/java_static_initializers.cpp b/jbmc/src/java_bytecode/java_static_initializers.cpp
index c2410c8d2ff..61c0fcfaeed 100644
--- a/jbmc/src/java_bytecode/java_static_initializers.cpp
+++ b/jbmc/src/java_bytecode/java_static_initializers.cpp
@@ -293,11 +293,7 @@ static void create_clinit_wrapper_symbols(
 
   // Create symbol for the "clinit_wrapper"
   symbolt wrapper_method_symbol;
-  code_typet wrapper_method_type;
-  wrapper_method_type.return_type() = void_typet();
-  // Ensure the parameters property is there
-  // to avoid trouble in irept comparisons
-  wrapper_method_type.parameters();
+  code_typet wrapper_method_type({}, void_typet());
   wrapper_method_symbol.name = clinit_wrapper_name(class_name);
   wrapper_method_symbol.pretty_name = wrapper_method_symbol.name;
   wrapper_method_symbol.base_name = "clinit_wrapper";
@@ -717,8 +713,7 @@ void stub_global_initializer_factoryt::create_stub_global_initializer_symbols(
       "a class cannot be both incomplete, and so have stub static fields, and "
       "also define a static initializer");
 
-    code_typet thunk_type;
-    thunk_type.return_type() = void_typet();
+    code_typet thunk_type({}, void_typet());
 
     symbolt static_init_symbol;
     static_init_symbol.name = static_init_name;
diff --git a/jbmc/src/java_bytecode/java_string_library_preprocess.cpp b/jbmc/src/java_bytecode/java_string_library_preprocess.cpp
index 4c8e3088730..a610681b504 100644
--- a/jbmc/src/java_bytecode/java_string_library_preprocess.cpp
+++ b/jbmc/src/java_bytecode/java_string_library_preprocess.cpp
@@ -1611,9 +1611,7 @@ codet java_string_library_preprocesst::make_object_get_class_code(
     "java::java.lang.Class.forName:(Ljava/lang/String;)Ljava/lang/Class;");
   fun_call.lhs()=class1;
   fun_call.arguments().push_back(string1);
-  code_typet fun_type;
-  fun_type.parameters().push_back(code_typet::parametert(string_ptr_type));
-  fun_type.return_type()=class_type;
+  code_typet fun_type({code_typet::parametert(string_ptr_type)}, class_type);
   fun_call.function().type()=fun_type;
   code.add(fun_call, loc);
 
diff --git a/jbmc/src/java_bytecode/java_types.cpp b/jbmc/src/java_bytecode/java_types.cpp
index e83254e6962..dc838eadd8d 100644
--- a/jbmc/src/java_bytecode/java_types.cpp
+++ b/jbmc/src/java_bytecode/java_types.cpp
@@ -493,24 +493,21 @@ typet java_type_from_string(
       if(e_pos==std::string::npos)
         return nil_typet();
 
-      code_typet result;
-
-      result.return_type()=
-        java_type_from_string(
-          std::string(src, e_pos+1, std::string::npos),
-          class_name_prefix);
+      typet return_type = java_type_from_string(
+        std::string(src, e_pos + 1, std::string::npos), class_name_prefix);
 
       std::vector<typet> param_types =
         parse_list_types(src.substr(0, e_pos + 1), class_name_prefix, '(', ')');
 
       // create parameters for each type
+      code_typet::parameterst parameters;
       std::transform(
         param_types.begin(),
         param_types.end(),
-        std::back_inserter(result.parameters()),
+        std::back_inserter(parameters),
         [](const typet &type) { return code_typet::parametert(type); });
 
-      return result;
+      return code_typet(std::move(parameters), std::move(return_type));
     }
 
   case '[': // array type
diff --git a/jbmc/unit/java-testing-utils/module_dependencies.txt b/jbmc/unit/java-testing-utils/module_dependencies.txt
new file mode 100644
index 00000000000..8a8c7bc5a68
--- /dev/null
+++ b/jbmc/unit/java-testing-utils/module_dependencies.txt
@@ -0,0 +1,6 @@
+goto-programs
+java_bytecode
+java-testing-utils
+langapi # should go away
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/ci_lazy_methods/module_dependencies.txt b/jbmc/unit/java_bytecode/ci_lazy_methods/module_dependencies.txt
new file mode 100644
index 00000000000..0bfc016ae2b
--- /dev/null
+++ b/jbmc/unit/java_bytecode/ci_lazy_methods/module_dependencies.txt
@@ -0,0 +1,3 @@
+ci_lazy_methods
+java-testing-utils
+testing-utils
diff --git a/jbmc/unit/java_bytecode/goto-programs/module_dependencies.txt b/jbmc/unit/java_bytecode/goto-programs/module_dependencies.txt
new file mode 100644
index 00000000000..5cf97f68743
--- /dev/null
+++ b/jbmc/unit/java_bytecode/goto-programs/module_dependencies.txt
@@ -0,0 +1,4 @@
+goto-programs
+java-testing-utils
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/goto_program_generics/module_dependencies.txt b/jbmc/unit/java_bytecode/goto_program_generics/module_dependencies.txt
new file mode 100644
index 00000000000..37a3752f982
--- /dev/null
+++ b/jbmc/unit/java_bytecode/goto_program_generics/module_dependencies.txt
@@ -0,0 +1,4 @@
+goto_program_generics
+java-testing-utils
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/inherited_static_fields/module_dependencies.txt b/jbmc/unit/java_bytecode/inherited_static_fields/module_dependencies.txt
new file mode 100644
index 00000000000..b633e9235a2
--- /dev/null
+++ b/jbmc/unit/java_bytecode/inherited_static_fields/module_dependencies.txt
@@ -0,0 +1,4 @@
+inherited_static_fields
+java-testing-utils
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/java_bytecode_convert_class/module_dependencies.txt b/jbmc/unit/java_bytecode/java_bytecode_convert_class/module_dependencies.txt
index 87cf9849bbf..4cbf833a097 100644
--- a/jbmc/unit/java_bytecode/java_bytecode_convert_class/module_dependencies.txt
+++ b/jbmc/unit/java_bytecode/java_bytecode_convert_class/module_dependencies.txt
@@ -1,3 +1,4 @@
 java-testing-utils
 testing-utils
 java_bytecode
+util
diff --git a/jbmc/unit/java_bytecode/java_bytecode_convert_method/module_dependencies.txt b/jbmc/unit/java_bytecode/java_bytecode_convert_method/module_dependencies.txt
new file mode 100644
index 00000000000..e3a60fcd031
--- /dev/null
+++ b/jbmc/unit/java_bytecode/java_bytecode_convert_method/module_dependencies.txt
@@ -0,0 +1,6 @@
+goto-programs
+java_bytecode
+java_bytecode_convert_method
+java-testing-utils
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/java_bytecode_parse_generics/module_dependencies.txt b/jbmc/unit/java_bytecode/java_bytecode_parse_generics/module_dependencies.txt
new file mode 100644
index 00000000000..5efcb3b2958
--- /dev/null
+++ b/jbmc/unit/java_bytecode/java_bytecode_parse_generics/module_dependencies.txt
@@ -0,0 +1,3 @@
+java_bytecode_parse_generics
+java-testing-utils
+testing-utils
diff --git a/jbmc/unit/java_bytecode/java_bytecode_parse_lambdas/module_dependencies.txt b/jbmc/unit/java_bytecode/java_bytecode_parse_lambdas/module_dependencies.txt
new file mode 100644
index 00000000000..b51f2e5f97a
--- /dev/null
+++ b/jbmc/unit/java_bytecode/java_bytecode_parse_lambdas/module_dependencies.txt
@@ -0,0 +1,6 @@
+java_bytecode
+java_bytecode_parse_lambdas
+java-testing-utils
+langapi # should go away
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/java_object_factory/module_dependencies.txt b/jbmc/unit/java_bytecode/java_object_factory/module_dependencies.txt
new file mode 100644
index 00000000000..c4380fa26bd
--- /dev/null
+++ b/jbmc/unit/java_bytecode/java_object_factory/module_dependencies.txt
@@ -0,0 +1,5 @@
+java_bytecode
+java_object_factory
+langapi # should go away
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/java_replace_nondet/module_dependencies.txt b/jbmc/unit/java_bytecode/java_replace_nondet/module_dependencies.txt
new file mode 100644
index 00000000000..b41e1a35ecb
--- /dev/null
+++ b/jbmc/unit/java_bytecode/java_replace_nondet/module_dependencies.txt
@@ -0,0 +1,7 @@
+goto-instrument
+goto-programs
+java_bytecode
+java_replace_nondet
+java-testing-utils
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/java_string_library_preprocess/module_dependencies.txt b/jbmc/unit/java_bytecode/java_string_library_preprocess/module_dependencies.txt
new file mode 100644
index 00000000000..69779082f81
--- /dev/null
+++ b/jbmc/unit/java_bytecode/java_string_library_preprocess/module_dependencies.txt
@@ -0,0 +1,5 @@
+java_bytecode
+java_string_library_preprocess
+langapi # should go away
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/java_types/module_dependencies.txt b/jbmc/unit/java_bytecode/java_types/module_dependencies.txt
new file mode 100644
index 00000000000..cb9d02b1529
--- /dev/null
+++ b/jbmc/unit/java_bytecode/java_types/module_dependencies.txt
@@ -0,0 +1,3 @@
+java_bytecode
+java_types
+testing-utils
diff --git a/jbmc/unit/java_bytecode/java_virtual_functions/module_dependencies.txt b/jbmc/unit/java_bytecode/java_virtual_functions/module_dependencies.txt
new file mode 100644
index 00000000000..b139ad5e0b6
--- /dev/null
+++ b/jbmc/unit/java_bytecode/java_virtual_functions/module_dependencies.txt
@@ -0,0 +1,7 @@
+goto-instrument
+goto-programs
+java_bytecode
+java_virtual_functions
+java-testing-utils
+testing-utils
+util
diff --git a/jbmc/unit/java_bytecode/module_dependencies.txt b/jbmc/unit/java_bytecode/module_dependencies.txt
new file mode 100644
index 00000000000..7c65cd85bde
--- /dev/null
+++ b/jbmc/unit/java_bytecode/module_dependencies.txt
@@ -0,0 +1,2 @@
+java_bytecode
+testing-utils
diff --git a/jbmc/unit/pointer-analysis/module_dependencies.txt b/jbmc/unit/pointer-analysis/module_dependencies.txt
new file mode 100644
index 00000000000..fb8b993d5dd
--- /dev/null
+++ b/jbmc/unit/pointer-analysis/module_dependencies.txt
@@ -0,0 +1,6 @@
+goto-programs
+java_bytecode
+langapi # should go away
+pointer-analysis
+testing-utils
+util
diff --git a/jbmc/unit/solvers/refinement/string_constraint_instantiation/module_dependencies.txt b/jbmc/unit/solvers/refinement/string_constraint_instantiation/module_dependencies.txt
new file mode 100644
index 00000000000..0741e46c2df
--- /dev/null
+++ b/jbmc/unit/solvers/refinement/string_constraint_instantiation/module_dependencies.txt
@@ -0,0 +1,7 @@
+java_bytecode
+langapi # should go away
+solvers/refinement
+solvers/sat
+string_constraint_instantiation
+testing-utils
+util
diff --git a/jbmc/unit/solvers/refinement/string_refinement/dependency_graph.cpp b/jbmc/unit/solvers/refinement/string_refinement/dependency_graph.cpp
index de6bd2d69e6..10abe9a6184 100644
--- a/jbmc/unit/solvers/refinement/string_refinement/dependency_graph.cpp
+++ b/jbmc/unit/solvers/refinement/string_refinement/dependency_graph.cpp
@@ -58,7 +58,12 @@ SCENARIO("dependency_graph", "[core][solvers][refinement][string_refinement]")
     const symbol_exprt lhs("lhs", unsignedbv_typet(32));
     const symbol_exprt lhs2("lhs2", unsignedbv_typet(32));
     const symbol_exprt lhs3("lhs3", unsignedbv_typet(32));
-    code_typet fun_type;
+    code_typet fun_type(
+      {code_typet::parametert(length_type()),
+       code_typet::parametert(pointer_type(java_char_type())),
+       code_typet::parametert(string_type),
+       code_typet::parametert(string_type)},
+      unsignedbv_typet(32));
 
     // fun1 is s3 = s1.concat(s2)
     function_application_exprt fun1(fun_type);
diff --git a/jbmc/unit/solvers/refinement/string_refinement/module_dependencies.txt b/jbmc/unit/solvers/refinement/string_refinement/module_dependencies.txt
new file mode 100644
index 00000000000..0c66e23bb4a
--- /dev/null
+++ b/jbmc/unit/solvers/refinement/string_refinement/module_dependencies.txt
@@ -0,0 +1,6 @@
+java_bytecode
+langapi # should go away
+string_refinement
+solvers/refinement
+testing-utils
+util
diff --git a/jbmc/unit/util/module_dependencies.txt b/jbmc/unit/util/module_dependencies.txt
new file mode 100644
index 00000000000..f2b17a21bf1
--- /dev/null
+++ b/jbmc/unit/util/module_dependencies.txt
@@ -0,0 +1,4 @@
+java_bytecode
+java-testing-utils
+testing-utils
+util
diff --git a/src/ansi-c/ansi_c_entry_point.cpp b/src/ansi-c/ansi_c_entry_point.cpp
index f15a3124f55..0942b4ca658 100644
--- a/src/ansi-c/ansi_c_entry_point.cpp
+++ b/src/ansi-c/ansi_c_entry_point.cpp
@@ -445,8 +445,7 @@ bool generate_ansi_c_start_function(
   // add the entry point symbol
   symbolt new_symbol;
 
-  code_typet main_type;
-  main_type.return_type()=empty_typet();
+  code_typet main_type({}, empty_typet());
 
   new_symbol.name=goto_functionst::entry_point();
   new_symbol.type.swap(main_type);
diff --git a/src/ansi-c/c_typecheck_expr.cpp b/src/ansi-c/c_typecheck_expr.cpp
index 81d6f7a1e7e..bfd7ec0f94a 100644
--- a/src/ansi-c/c_typecheck_expr.cpp
+++ b/src/ansi-c/c_typecheck_expr.cpp
@@ -450,10 +450,8 @@ void c_typecheck_baset::typecheck_expr_builtin_va_arg(exprt &expr)
   typet arg_type=expr.type();
   typecheck_type(arg_type);
 
-  code_typet new_type;
-  new_type.return_type().swap(arg_type);
-  new_type.parameters().resize(1);
-  new_type.parameters()[0].type()=pointer_type(void_type());
+  code_typet new_type(
+    {code_typet::parametert(pointer_type(void_type()))}, std::move(arg_type));
 
   assert(expr.operands().size()==1);
   exprt arg=expr.op0();
diff --git a/src/cbmc/symex_coverage.cpp b/src/cbmc/symex_coverage.cpp
index 0ecd58b1083..ddef86378d9 100644
--- a/src/cbmc/symex_coverage.cpp
+++ b/src/cbmc/symex_coverage.cpp
@@ -173,8 +173,6 @@ goto_program_coverage_recordt::goto_program_coverage_recordt(
 
   code_typet sig_type=
     original_return_type(ns.get_symbol_table(), gf_it->first);
-  if(sig_type.is_nil())
-    sig_type=gf_it->second.type;
   xml.set_attribute("signature",
                     from_type(ns, gf_it->first, sig_type));
 
diff --git a/src/cpp/cpp_typecheck_expr.cpp b/src/cpp/cpp_typecheck_expr.cpp
index 3a5ac9cd9c0..cb1d28fbeb0 100644
--- a/src/cpp/cpp_typecheck_expr.cpp
+++ b/src/cpp/cpp_typecheck_expr.cpp
@@ -1446,10 +1446,9 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
+      code_typet t(
+        {code_typet::parametert(ptr_arg.type())}, ptr_arg.type().subtype());
       t.make_ellipsis();
-      t.return_type()=ptr_arg.type().subtype();
       result.type()=t;
       expr.swap(result);
       return;
@@ -1480,10 +1479,10 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(code_typet::parametert(signed_int_type()));
-      t.return_type()=ptr_arg.type().subtype();
+      code_typet t(
+        {code_typet::parametert(ptr_arg.type()),
+         code_typet::parametert(signed_int_type())},
+        ptr_arg.type().subtype());
       result.type()=t;
       expr.swap(result);
       return;
@@ -1514,12 +1513,11 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(
-        code_typet::parametert(ptr_arg.type().subtype()));
-      t.parameters().push_back(code_typet::parametert(signed_int_type()));
-      t.return_type()=empty_typet();
+      code_typet t(
+        {code_typet::parametert(ptr_arg.type()),
+         code_typet::parametert(ptr_arg.type().subtype()),
+         code_typet::parametert(signed_int_type())},
+        empty_typet());
       result.type()=t;
       expr.swap(result);
       return;
@@ -1550,12 +1548,11 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(
-        code_typet::parametert(ptr_arg.type().subtype()));
-      t.parameters().push_back(code_typet::parametert(signed_int_type()));
-      t.return_type()=ptr_arg.type().subtype();
+      code_typet t(
+        {code_typet::parametert(ptr_arg.type()),
+         code_typet::parametert(ptr_arg.type().subtype()),
+         code_typet::parametert(signed_int_type())},
+        ptr_arg.type().subtype());
       result.type()=t;
       expr.swap(result);
       return;
@@ -1594,11 +1591,11 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(code_typet::parametert(signed_int_type()));
-      t.return_type()=empty_typet();
+      code_typet t(
+        {code_typet::parametert(ptr_arg.type()),
+         code_typet::parametert(ptr_arg.type()),
+         code_typet::parametert(signed_int_type())},
+        empty_typet());
       result.type()=t;
       expr.swap(result);
       return;
@@ -1643,12 +1640,12 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(code_typet::parametert(signed_int_type()));
-      t.return_type()=empty_typet();
+      code_typet t(
+        {code_typet::parametert(ptr_arg.type()),
+         code_typet::parametert(ptr_arg.type()),
+         code_typet::parametert(ptr_arg.type()),
+         code_typet::parametert(signed_int_type())},
+        empty_typet());
       result.type()=t;
       expr.swap(result);
       return;
@@ -1698,20 +1695,19 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
+      code_typet::parameterst parameters;
+      parameters.push_back(code_typet::parametert(ptr_arg.type()));
+      parameters.push_back(code_typet::parametert(ptr_arg.type()));
 
       if(identifier=="__atomic_compare_exchange")
-        t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
+        parameters.push_back(code_typet::parametert(ptr_arg.type()));
       else
-        t.parameters().push_back(
-          code_typet::parametert(ptr_arg.type().subtype()));
+        parameters.push_back(code_typet::parametert(ptr_arg.type().subtype()));
 
-      t.parameters().push_back(code_typet::parametert(c_bool_type()));
-      t.parameters().push_back(code_typet::parametert(signed_int_type()));
-      t.parameters().push_back(code_typet::parametert(signed_int_type()));
-      t.return_type()=c_bool_type();
+      parameters.push_back(code_typet::parametert(c_bool_type()));
+      parameters.push_back(code_typet::parametert(signed_int_type()));
+      parameters.push_back(code_typet::parametert(signed_int_type()));
+      code_typet t(std::move(parameters), c_bool_type());
       result.type()=t;
       expr.swap(result);
       return;
@@ -1744,10 +1740,9 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
+      code_typet t(
+        {code_typet::parametert(ptr_arg.type())}, ptr_arg.type().subtype());
       t.make_ellipsis();
-      t.return_type()=ptr_arg.type().subtype();
       result.type()=t;
       expr.swap(result);
       return;
@@ -1780,10 +1775,9 @@ void cpp_typecheckt::typecheck_expr_cpp_name(
       symbol_exprt result;
       result.add_source_location()=source_location;
       result.set_identifier(identifier);
-      code_typet t;
-      t.parameters().push_back(code_typet::parametert(ptr_arg.type()));
+      code_typet t(
+        {code_typet::parametert(ptr_arg.type())}, ptr_arg.type().subtype());
       t.make_ellipsis();
-      t.return_type()=ptr_arg.type().subtype();
       result.type()=t;
       expr.swap(result);
       return;
diff --git a/src/cpp/cpp_typecheck_resolve.cpp b/src/cpp/cpp_typecheck_resolve.cpp
index 3a74207a96e..c9b830be888 100644
--- a/src/cpp/cpp_typecheck_resolve.cpp
+++ b/src/cpp/cpp_typecheck_resolve.cpp
@@ -611,18 +611,14 @@ void cpp_typecheck_resolvet::make_constructors(
 
       // 1. no arguments, default initialization
       {
-        code_typet t1;
-        t1.return_type()=it->type();
+        code_typet t1({}, it->type());
         exprt pod_constructor1("pod_constructor", t1);
         new_identifiers.push_back(pod_constructor1);
       }
 
       // 2. one argument, copy/conversion
       {
-        code_typet t2;
-        t2.return_type()=it->type();
-        t2.parameters().resize(1);
-        t2.parameters()[0].type()=it->type();
+        code_typet t2({code_typet::parametert(it->type())}, it->type());
         exprt pod_constructor2("pod_constructor", t2);
         new_identifiers.push_back(pod_constructor2);
       }
@@ -630,10 +626,7 @@ void cpp_typecheck_resolvet::make_constructors(
       // enums, in addition, can also be constructed from int
       if(symbol_type.id()==ID_c_enum_tag)
       {
-        code_typet t3;
-        t3.return_type()=it->type();
-        t3.parameters().resize(1);
-        t3.parameters()[0].type()=signed_int_type();
+        code_typet t3({code_typet::parametert(signed_int_type())}, it->type());
         exprt pod_constructor3("pod_constructor", t3);
         new_identifiers.push_back(pod_constructor3);
       }
diff --git a/src/goto-cc/linker_script_merge.cpp b/src/goto-cc/linker_script_merge.cpp
index 459dbdc7bf2..fd0da16dbe3 100644
--- a/src/goto-cc/linker_script_merge.cpp
+++ b/src/goto-cc/linker_script_merge.cpp
@@ -593,8 +593,7 @@ int linker_script_merget::ls_data2instructions(
   for(const auto &d : data["regions"].array)
   {
     code_function_callt f;
-    code_typet void_t;
-    void_t.return_type()=empty_typet();
+    code_typet void_t({}, empty_typet());
     f.function()=symbol_exprt(CPROVER_PREFIX "allocated_memory", void_t);
     unsigned start=safe_string2unsigned(d["start"].value);
     unsigned size=safe_string2unsigned(d["size"].value);
@@ -620,8 +619,7 @@ int linker_script_merget::ls_data2instructions(
     sym.name=CPROVER_PREFIX "allocated_memory";
     sym.pretty_name=CPROVER_PREFIX "allocated_memory";
     sym.is_lvalue=sym.is_static_lifetime=true;
-    code_typet void_t;
-    void_t.return_type()=empty_typet();
+    code_typet void_t({}, empty_typet());
     sym.type=void_t;
     symbol_table.add(sym);
   }
diff --git a/src/goto-instrument/goto_program2code.cpp b/src/goto-instrument/goto_program2code.cpp
index d0339ec3ae8..2a485e1ca00 100644
--- a/src/goto-instrument/goto_program2code.cpp
+++ b/src/goto-instrument/goto_program2code.cpp
@@ -228,8 +228,7 @@ goto_programt::const_targett goto_program2codet::convert_instruction(
     case ATOMIC_END:
       {
         code_function_callt f;
-        code_typet void_t;
-        void_t.return_type()=empty_typet();
+        code_typet void_t({}, empty_typet());
         f.function()=symbol_exprt(
             target->is_atomic_begin() ?
             "__CPROVER_atomic_begin" :
@@ -328,7 +327,7 @@ goto_programt::const_targett goto_program2codet::convert_assign_varargs(
   if(r.id()==ID_constant &&
      (r.is_zero() || to_constant_expr(r).get_value()==ID_NULL))
   {
-    f.function()=symbol_exprt("va_end", code_typet());
+    f.function() = symbol_exprt("va_end", code_typet({}, empty_typet()));
     f.arguments().push_back(this_va_list_expr);
     f.arguments().back().type().id(ID_gcc_builtin_va_list);
 
@@ -336,7 +335,7 @@ goto_programt::const_targett goto_program2codet::convert_assign_varargs(
   }
   else if(r.id()==ID_address_of)
   {
-    f.function()=symbol_exprt("va_start", code_typet());
+    f.function() = symbol_exprt("va_start", code_typet({}, empty_typet()));
     f.arguments().push_back(this_va_list_expr);
     f.arguments().back().type().id(ID_gcc_builtin_va_list);
     f.arguments().push_back(to_address_of_expr(r).object());
@@ -346,12 +345,13 @@ goto_programt::const_targett goto_program2codet::convert_assign_varargs(
   else if(r.id()==ID_side_effect &&
           to_side_effect_expr(r).get_statement()==ID_gcc_builtin_va_arg_next)
   {
-    f.function()=symbol_exprt("va_arg", code_typet());
+    f.function() = symbol_exprt("va_arg", code_typet({}, empty_typet()));
     f.arguments().push_back(this_va_list_expr);
     f.arguments().back().type().id(ID_gcc_builtin_va_list);
 
     side_effect_expr_function_callt type_of;
-    type_of.function()=symbol_exprt("__typeof__", code_typet());
+    type_of.function() =
+      symbol_exprt("__typeof__", code_typet({}, empty_typet()));
 
     // if the return value is used, the next instruction will be assign
     goto_programt::const_targett next=target;
@@ -393,7 +393,7 @@ goto_programt::const_targett goto_program2codet::convert_assign_varargs(
   }
   else
   {
-    f.function()=symbol_exprt("va_copy", code_typet());
+    f.function() = symbol_exprt("va_copy", code_typet({}, empty_typet()));
     f.arguments().push_back(this_va_list_expr);
     f.arguments().back().type().id(ID_gcc_builtin_va_list);
     f.arguments().push_back(r);
@@ -1374,7 +1374,8 @@ goto_programt::const_targett goto_program2codet::convert_start_thread(
     code_function_callt f;
     // we don't bother setting the type
     f.lhs()=cf.lhs();
-    f.function()=symbol_exprt("pthread_create", code_typet());
+    f.function() =
+      symbol_exprt("pthread_create", code_typet({}, empty_typet()));
     const null_pointer_exprt n(pointer_type(empty_typet()));
     f.arguments().push_back(n);
     f.arguments().push_back(n);
@@ -1947,8 +1948,7 @@ void goto_program2codet::cleanup_expr(exprt &expr, bool no_typecast)
           base_name="nondet_"+std::to_string(count);
         }
 
-        code_typet code_type;
-        code_type.return_type()=expr.type();
+        code_typet code_type({}, expr.type());
 
         symbolt symbol;
         symbol.base_name=base_name;
diff --git a/src/goto-programs/builtin_functions.cpp b/src/goto-programs/builtin_functions.cpp
index 52c3cf2650c..934b610e728 100644
--- a/src/goto-programs/builtin_functions.cpp
+++ b/src/goto-programs/builtin_functions.cpp
@@ -1588,7 +1588,6 @@ void goto_convertt::do_function_call_symbol(
 
     if(!symbol_table.has_symbol(name))
     {
-      code_typet();
       symbolt new_symbol;
       new_symbol.base_name=name;
       new_symbol.name=name;
diff --git a/src/goto-programs/remove_asm.cpp b/src/goto-programs/remove_asm.cpp
index c863adde77f..e67602fff2a 100644
--- a/src/goto-programs/remove_asm.cpp
+++ b/src/goto-programs/remove_asm.cpp
@@ -78,8 +78,7 @@ void remove_asmt::gcc_asm_function_call(
     }
   }
 
-  code_typet fkt_type;
-  fkt_type.return_type()=void_typet();
+  code_typet fkt_type({}, void_typet());
   fkt_type.make_ellipsis();
 
   symbol_exprt fkt(function_identifier, fkt_type);
diff --git a/src/goto-programs/remove_returns.cpp b/src/goto-programs/remove_returns.cpp
index 1544114d37f..76f4e77354d 100644
--- a/src/goto-programs/remove_returns.cpp
+++ b/src/goto-programs/remove_returns.cpp
@@ -290,13 +290,14 @@ void remove_returns(goto_modelt &goto_model)
 /// \param symbol_table: global symbol table
 /// \param function_id: function to get the type of
 /// \return the function's type with its `return_type()` restored to its
-///   original value if a \#return_value variable exists, or nil otherwise
+///   original value
 code_typet original_return_type(
   const symbol_table_baset &symbol_table,
   const irep_idt &function_id)
 {
-  code_typet type;
-  type.make_nil();
+  // look up the function symbol
+  const symbolt &function_symbol = symbol_table.lookup_ref(function_id);
+  code_typet type = to_code_type(function_symbol.type);
 
   // do we have X#return_value?
   std::string rv_name=id2string(function_id)+RETURN_VALUE_SUFFIX;
@@ -304,14 +305,8 @@ code_typet original_return_type(
   symbol_tablet::symbolst::const_iterator rv_it=
     symbol_table.symbols.find(rv_name);
 
-  if(rv_it!=symbol_table.symbols.end())
-  {
-    // look up the function symbol
-    const symbolt &function_symbol=symbol_table.lookup_ref(function_id);
-
-    type=to_code_type(function_symbol.type);
-    type.return_type()=rv_it->second.type;
-  }
+  if(rv_it != symbol_table.symbols.end())
+    type.return_type() = rv_it->second.type;
 
   return type;
 }
diff --git a/src/jsil/jsil_entry_point.cpp b/src/jsil/jsil_entry_point.cpp
index 43f60bd1950..80f787ca9c2 100644
--- a/src/jsil/jsil_entry_point.cpp
+++ b/src/jsil/jsil_entry_point.cpp
@@ -26,8 +26,7 @@ static void create_initialize(symbol_tablet &symbol_table)
   initialize.base_name = INITIALIZE_FUNCTION;
   initialize.mode="jsil";
 
-  code_typet type;
-  type.return_type()=empty_typet();
+  code_typet type({}, empty_typet());
   initialize.type=type;
 
   code_blockt init_code;
@@ -152,8 +151,7 @@ bool jsil_entry_point(
   // add "main"
   symbolt new_symbol;
 
-  code_typet main_type;
-  main_type.return_type()=empty_typet();
+  code_typet main_type({}, empty_typet());
 
   new_symbol.name=goto_functionst::entry_point();
   new_symbol.type.swap(main_type);
diff --git a/src/util/std_types.h b/src/util/std_types.h
index ca2c0934685..591a91d4de4 100644
--- a/src/util/std_types.h
+++ b/src/util/std_types.h
@@ -758,8 +758,36 @@ inline c_enum_tag_typet &to_c_enum_tag_type(typet &type)
 class code_typet:public typet
 {
 public:
+  class parametert;
+  typedef std::vector<parametert> parameterst;
+
+  /// Constructs a new code type, i.e. function type
+  /// \param _parameters: the vector of function parameters
+  /// \param _return_type: the return type
+  code_typet(parameterst &&_parameters, typet &&_return_type) : typet(ID_code)
+  {
+    parameters().swap(_parameters);
+    return_type().swap(_return_type);
+  }
+
+  /// Constructs a new code type, i.e. function type
+  /// \param _parameters: the vector of function parameters
+  /// \param _return_type: the return type
+  code_typet(parameterst &&_parameters, const typet &_return_type)
+    : typet(ID_code)
+  {
+    parameters().swap(_parameters);
+    return_type() = _return_type;
+  }
+
+  /// \deprecated
+  DEPRECATED("Use the two argument constructor instead")
   code_typet():typet(ID_code)
   {
+    // make sure these properties are always there to avoid problems
+    // with irept comparisons
+    add(ID_parameters);
+    add_type(ID_return_type);
   }
 
   // used to be argumentt -- now uses standard terminology
@@ -858,8 +886,6 @@ class code_typet:public typet
     add(ID_parameters).remove(ID_ellipsis);
   }
 
-  typedef std::vector<parametert> parameterst;
-
   const typet &return_type() const
   {
     return find_type(ID_return_type);
diff --git a/unit/analyses/ai/module_dependencies.txt b/unit/analyses/ai/module_dependencies.txt
new file mode 100644
index 00000000000..093b56978cb
--- /dev/null
+++ b/unit/analyses/ai/module_dependencies.txt
@@ -0,0 +1,5 @@
+ai
+analyses
+ansi-c
+testing-utils
+util
diff --git a/unit/analyses/call_graph.cpp b/unit/analyses/call_graph.cpp
index ffefc5d93f6..67f6fa68a82 100644
--- a/unit/analyses/call_graph.cpp
+++ b/unit/analyses/call_graph.cpp
@@ -22,7 +22,7 @@ static symbolt create_void_function_symbol(
   const irep_idt &name,
   const codet &code)
 {
-  code_typet void_function_type;
+  code_typet void_function_type({}, empty_typet());
   symbolt function;
   function.name=name;
   function.type=void_function_type;
@@ -67,7 +67,7 @@ SCENARIO("call_graph",
     // void E() { }
 
     goto_modelt goto_model;
-    code_typet void_function_type;
+    code_typet void_function_type({}, empty_typet());
 
     {
       code_blockt calls;
diff --git a/unit/analyses/dependence_graph.cpp b/unit/analyses/dependence_graph.cpp
index 6ef65220485..84f9535bbf7 100644
--- a/unit/analyses/dependence_graph.cpp
+++ b/unit/analyses/dependence_graph.cpp
@@ -22,7 +22,7 @@ static symbolt create_void_function_symbol(
   const irep_idt &name,
   const codet &code)
 {
-  code_typet void_function_type;
+  code_typet void_function_type({}, empty_typet());
   symbolt function;
   function.name = name;
   function.type = void_function_type;
@@ -74,7 +74,7 @@ SCENARIO("dependence_graph", "[core][analyses][dependence_graph]")
     x_symbol.is_file_local = true;
     goto_model.symbol_table.add(x_symbol);
 
-    code_typet void_function_type;
+    code_typet void_function_type({}, empty_typet());
 
     code_blockt a_body;
     code_declt declare_x(x_symbol.symbol_expr());
diff --git a/unit/analyses/does_remove_const/module_dependencies.txt b/unit/analyses/does_remove_const/module_dependencies.txt
new file mode 100644
index 00000000000..cdcf3a17881
--- /dev/null
+++ b/unit/analyses/does_remove_const/module_dependencies.txt
@@ -0,0 +1,6 @@
+analyses
+ansi-c
+does_remove_const
+goto-programs
+testing-utils
+util
diff --git a/unit/analyses/module_dependencies.txt b/unit/analyses/module_dependencies.txt
new file mode 100644
index 00000000000..1edf1ff9596
--- /dev/null
+++ b/unit/analyses/module_dependencies.txt
@@ -0,0 +1,6 @@
+analyses
+ansi-c
+goto-programs
+langapi # should go away
+testing-utils
+util
diff --git a/unit/module_dependencies.txt b/unit/module_dependencies.txt
new file mode 100644
index 00000000000..1640922e72d
--- /dev/null
+++ b/unit/module_dependencies.txt
@@ -0,0 +1,15 @@
+ansi-c
+cbmc
+cpp
+goto-programs
+goto-symex
+json
+langapi # should go away
+solvers/flattening
+solvers/floatbv
+solvers/miniBDD
+solvers/prop
+solvers/sat
+solvers/smt2
+testing-utils
+util
diff --git a/unit/solvers/refinement/string_constraint_generator_valueof/module_dependencies.txt b/unit/solvers/refinement/string_constraint_generator_valueof/module_dependencies.txt
new file mode 100644
index 00000000000..ee346fe1dd4
--- /dev/null
+++ b/unit/solvers/refinement/string_constraint_generator_valueof/module_dependencies.txt
@@ -0,0 +1,4 @@
+solvers/refinement
+string_constraint_generator_valueof
+testing-utils
+util
diff --git a/unit/solvers/refinement/string_refinement/module_dependencies.txt b/unit/solvers/refinement/string_refinement/module_dependencies.txt
new file mode 100644
index 00000000000..863836fb0c3
--- /dev/null
+++ b/unit/solvers/refinement/string_refinement/module_dependencies.txt
@@ -0,0 +1,4 @@
+solvers/refinement
+string_refinement
+testing-utils
+util
diff --git a/unit/testing-utils/module_dependencies.txt b/unit/testing-utils/module_dependencies.txt
new file mode 100644
index 00000000000..b5ccfdd0368
--- /dev/null
+++ b/unit/testing-utils/module_dependencies.txt
@@ -0,0 +1,3 @@
+ansi-c
+testing-utils
+util
diff --git a/unit/util/expr_cast/module_dependencies.txt b/unit/util/expr_cast/module_dependencies.txt
new file mode 100644
index 00000000000..ec9599d1d19
--- /dev/null
+++ b/unit/util/expr_cast/module_dependencies.txt
@@ -0,0 +1,3 @@
+expr_casts
+testing-utils
+util
diff --git a/unit/util/module_dependencies.txt b/unit/util/module_dependencies.txt
new file mode 100644
index 00000000000..abf92b3762e
--- /dev/null
+++ b/unit/util/module_dependencies.txt
@@ -0,0 +1,2 @@
+testing-utils
+util
diff --git a/unit/util/string_utils/module_dependencies.txt b/unit/util/string_utils/module_dependencies.txt
new file mode 100644
index 00000000000..7fd7f16f4f0
--- /dev/null
+++ b/unit/util/string_utils/module_dependencies.txt
@@ -0,0 +1,3 @@
+string_utils
+testing-utils
+util