+#if GDB_SELF_TEST
+
+namespace selftests {
+namespace filename_language {
+
+static void test_filename_language ()
+{
+ /* This test messes up the filename_language_table global. */
+ scoped_restore restore_flt = make_scoped_restore (&filename_language_table);
+
+ /* Test deducing an unknown extension. */
+ language lang = deduce_language_from_filename ("myfile.blah");
+ SELF_CHECK (lang == language_unknown);
+
+ /* Test deducing a known extension. */
+ lang = deduce_language_from_filename ("myfile.c");
+ SELF_CHECK (lang == language_c);
+
+ /* Test adding a new extension using the internal API. */
+ add_filename_language (".blah", language_pascal);
+ lang = deduce_language_from_filename ("myfile.blah");
+ SELF_CHECK (lang == language_pascal);
+}
+
+static void
+test_set_ext_lang_command ()
+{
+ /* This test messes up the filename_language_table global. */
+ scoped_restore restore_flt = make_scoped_restore (&filename_language_table);
+
+ /* Confirm that the .hello extension is not known. */
+ language lang = deduce_language_from_filename ("cake.hello");
+ SELF_CHECK (lang == language_unknown);
+
+ /* Test adding a new extension using the CLI command. */
+ gdb::unique_xmalloc_ptr<char> args_holder (xstrdup (".hello rust"));
+ ext_args = args_holder.get ();
+ set_ext_lang_command (NULL, 1, NULL);
+
+ lang = deduce_language_from_filename ("cake.hello");
+ SELF_CHECK (lang == language_rust);
+
+ /* Test overriding an existing extension using the CLI command. */
+ int size_before = filename_language_table.size ();
+ args_holder.reset (xstrdup (".hello pascal"));
+ ext_args = args_holder.get ();
+ set_ext_lang_command (NULL, 1, NULL);
+ int size_after = filename_language_table.size ();
+
+ lang = deduce_language_from_filename ("cake.hello");
+ SELF_CHECK (lang == language_pascal);
+ SELF_CHECK (size_before == size_after);
+}
+
+} /* namespace filename_language */
+} /* namespace selftests */
+
+#endif /* GDB_SELF_TEST */
+