main: Pass script on CLI instead of via environment

Environment variables aren't the best option to pass parameters
to a process (wouldn't it be "fun" if SHELL_PERF_MODULE appeared
in a regular user session?).

Instead, use a (hidden) --automation-script command line flag to
specify a script file that should be used to drive an automated
session.

As a side effect, the script no longer has to be relative to the
main module itself, so it will be possible to run scripts that
aren't bundled with the shell sources.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2812>

js/ui/main.js

@@ -326,9 +326,9 @@ async function _initializeUI() {
     }
 
     let perfModule;
-    const perfModuleName = GLib.getenv('SHELL_PERF_MODULE');
-    if (perfModuleName) {
-        perfModule = await import(`../perf/${perfModuleName}.js`);
+    const {automationScript} = global;
+    if (automationScript) {
+        perfModule = await import(automationScript.get_uri());
         if (perfModule.init)
             perfModule.init();
     }

src/gnome-shell-perf-tool.in

@@ -27,7 +27,6 @@ def show_version(option, opt_str, value, parser):
 def start_shell(wrap=None, perf_output=None):
     # Set up environment
     env = dict(os.environ)
-    env['SHELL_PERF_MODULE'] = options.perf
 
     filters = ['Gnome-shell-perf-helper'] + options.extra_filter
     env['MUTTER_WM_CLASS_FILTER'] = ','.join(filters)
@@ -45,6 +44,9 @@ def start_shell(wrap=None, perf_output=None):
         args += wrap.split(' ')
     args.append(os.path.join(self_dir, 'gnome-shell'))
 
+    args.append('--automation-script')
+    args.append(options.script)
+
     args.append('--force-animations')
 
     if options.replace:
@@ -173,7 +175,7 @@ def gnome_hwtest_log(*args):
     subprocess.check_call(command)
 
 def run_performance_test(wrap=None):
-    iters = options.perf_iters
+    iters = options.test_iters
     if options.perf_warmup:
         iters += 1
 
@@ -286,10 +288,10 @@ def run_performance_test(wrap=None):
 # Main program
 
 parser = argparse.ArgumentParser()
-parser.add_argument("--perf",
-                    help="Specify the name of a performance module to run")
-parser.add_argument("--perf-iters", type=int, metavar="ITERS",
-                    help="Numbers of iterations of performance module to run",
+parser.add_argument("--script",
+                    help="Specify the path to the automation script to run")
+parser.add_argument("--test-iters", type=int, metavar="ITERS",
+                    help="Numbers of iterations of the test to run",
                     default=1)
 parser.add_argument("--perf-warmup", action="store_true",
                     help="Run a dry run before performance tests")
@@ -321,16 +323,16 @@ parser.add_argument("--hotplug", action="store_true",
 
 options = parser.parse_args()
 
-if options.perf == None:
+if options.script == None:
     if options.hwtest:
-        options.perf = 'hwtest'
+        options.script = 'resource:///org/gnome/shell/perf/hwtest.js'
     else:
-        options.perf = 'core'
+        options.script = 'resource:///org/gnome/shell/perf/core.js'
 
 if options.extra_filter is None:
     options.extra_filter = []
 
-if options.perf == 'hwtest':
+if options.script == 'hwtest':
     options.extra_filter.append('Gedit')
 
 normal_exit = run_performance_test(wrap=options.wrap)

src/main.c

@@ -39,6 +39,7 @@ static gboolean is_gdm_mode = FALSE;
 static char *session_mode = NULL;
 static int caught_signal = 0;
 static gboolean force_animations = FALSE;
+static char *script_path = NULL;
 
 #define DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER 1
 #define DBUS_REQUEST_NAME_REPLY_ALREADY_OWNER 4
@@ -532,6 +533,12 @@ GOptionEntry gnome_shell_options[] = {
     N_("Force animations to be enabled"),
     NULL
   },
+  {
+    "automation-script", 0, G_OPTION_FLAG_HIDDEN, G_OPTION_ARG_FILENAME,
+    &script_path,
+    N_(""),
+    NULL
+  },
   { NULL }
 };
 
@@ -582,6 +589,8 @@ int
 main (int argc, char **argv)
 {
   g_autoptr (MetaContext) context = NULL;
+  g_autoptr (GFile) automation_script = NULL;
+  g_autofree char *cwd = NULL;
   GError *error = NULL;
   int ecode = EXIT_SUCCESS;
 
@@ -606,6 +615,7 @@ main (int argc, char **argv)
   meta_context_set_gnome_wm_keybindings (context, GNOME_WM_KEYBINDINGS);
 
   init_signal_handlers (context);
+  cwd = g_get_current_dir ();
   change_to_home_directory ();
 
   if (session_mode == NULL)
@@ -628,12 +638,16 @@ main (int argc, char **argv)
       dump_gjs_stack_on_signal (SIGSEGV);
     }
 
+  if (script_path)
+    automation_script = g_file_new_for_commandline_arg_and_cwd (script_path, cwd);
+
   /* Initialize the Shell global, including GjsContext
    * GjsContext will iterate the default main loop to
    * resolve internal modules.
    */
   _shell_global_init ("session-mode", session_mode,
                       "force-animations", force_animations,
+                      "automation-script", automation_script,
                       NULL);
 
   /* Setup Meta _after_ the Shell global to avoid GjsContext

src/shell-global.c

@@ -73,6 +73,7 @@ struct _ShellGlobal {
   char *userdatadir;
   GFile *userdatadir_path;
   GFile *runtime_state_path;
+  GFile *automation_script;
 
   ShellWindowTracker *window_tracker;
   ShellAppSystem *app_system;
@@ -120,6 +121,7 @@ enum {
   PROP_FRAME_FINISH_TIMESTAMP,
   PROP_SWITCHEROO_CONTROL,
   PROP_FORCE_ANIMATIONS,
+  PROP_AUTOMATION_SCRIPT,
 
   N_PROPS
 };
@@ -249,6 +251,9 @@ shell_global_set_property(GObject         *object,
     case PROP_FORCE_ANIMATIONS:
       global->force_animations = g_value_get_boolean (value);
       break;
+    case PROP_AUTOMATION_SCRIPT:
+      g_set_object (&global->automation_script, g_value_get_object (value));
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -338,6 +343,9 @@ shell_global_get_property(GObject         *object,
     case PROP_FORCE_ANIMATIONS:
       g_value_set_boolean (value, global->force_animations);
       break;
+    case PROP_AUTOMATION_SCRIPT:
+      g_value_set_object (value, global->automation_script);
+      break;
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -688,6 +696,13 @@ shell_global_class_init (ShellGlobalClass *klass)
                           FALSE,
                           G_PARAM_READWRITE  | G_PARAM_CONSTRUCT| G_PARAM_STATIC_STRINGS);
 
+  props[PROP_AUTOMATION_SCRIPT] =
+    g_param_spec_object ("automation-script",
+                         "automation-script",
+                         "Automation script to run after startup",
+                         G_TYPE_FILE,
+                         G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY | G_PARAM_STATIC_STRINGS);
+
   g_object_class_install_properties (gobject_class, N_PROPS, props);
 }
 

tests/meson.build

@@ -71,7 +71,7 @@ foreach perf_test : perf_tests
     args: [
       perf_tool,
       '--headless',
-      '--perf=@0@'.format(test_name),
+      '--script=@0@/js/perf/@1@.js'.format(meson.project_source_root(), test_name),
       options,
     ],
     is_parallel: false,