diff --git a/fish-rust/src/ffi.rs b/fish-rust/src/ffi.rs
index 380e8d682..84a9dc7a1 100644
--- a/fish-rust/src/ffi.rs
+++ b/fish-rust/src/ffi.rs
@@ -100,6 +100,14 @@
     generate!("io_chain_t")
 
     generate!("env_var_t")
+
+    generate!("function_get_definition_file")
+    generate!("function_get_copy_definition_file")
+    generate!("function_get_definition_lineno")
+    generate!("function_get_copy_definition_lineno")
+    generate!("function_get_annotated_definition")
+    generate!("function_is_copy")
+    generate!("function_exists")
 }
 
 impl parser_t {
diff --git a/src/function.cpp b/src/function.cpp
index d930b25fa..36218245b 100644
--- a/src/function.cpp
+++ b/src/function.cpp
@@ -165,6 +165,27 @@ function_properties_ref_t function_get_props(const wcstring &name) {
     return function_set.acquire()->get_props(name);
 }
 
+wcstring function_get_definition_file(const function_properties_t &props) {
+    return props.definition_file ? *props.definition_file : L"";
+}
+
+wcstring function_get_copy_definition_file(const function_properties_t &props) {
+    return props.copy_definition_file ? *props.copy_definition_file : L"";
+}
+bool function_is_copy(const function_properties_t &props) {
+    return props.is_copy;
+}
+int function_get_definition_lineno(const function_properties_t &props) {
+    return props.definition_lineno();
+}
+int function_get_copy_definition_lineno(const function_properties_t &props) {
+    return props.copy_definition_lineno;
+}
+
+wcstring function_get_annotated_definition(const function_properties_t &props, const wcstring &name) {
+    return props.annotated_definition(name);
+}
+
 function_properties_ref_t function_get_props_autoload(const wcstring &name, parser_t &parser) {
     parser.assert_can_execute();
     if (parser_keywords_is_reserved(name)) return nullptr;
diff --git a/src/function.h b/src/function.h
index 54b02931e..0df00ac8f 100644
--- a/src/function.h
+++ b/src/function.h
@@ -67,7 +67,8 @@ struct function_properties_t {
     wcstring annotated_definition(const wcstring &name) const;
 };
 
-using function_properties_ref_t = std::shared_ptr<const function_properties_t>;
+// FIXME: Morally, this is const, but cxx doesn't get it
+using function_properties_ref_t = std::shared_ptr<function_properties_t>;
 
 /// Add a function. This may mutate \p props to set is_autoload.
 void function_add(wcstring name, std::shared_ptr<function_properties_t> props);
@@ -78,6 +79,14 @@ void function_remove(const wcstring &name);
 /// \return the properties for a function, or nullptr if none. This does not trigger autoloading.
 function_properties_ref_t function_get_props(const wcstring &name);
 
+/// Guff to work around cxx not getting function_properties_t.
+wcstring function_get_definition_file(const function_properties_t &props);
+wcstring function_get_copy_definition_file(const function_properties_t &props);
+bool function_is_copy(const function_properties_t &props);
+int function_get_definition_lineno(const function_properties_t &props);
+int function_get_copy_definition_lineno(const function_properties_t &props);
+wcstring function_get_annotated_definition(const function_properties_t &props, const wcstring &name);
+
 /// \return the properties for a function, or nullptr if none, perhaps triggering autoloading.
 function_properties_ref_t function_get_props_autoload(const wcstring &name, parser_t &parser);