[util/hb-subset] Pre-parse font-face so we can use it during main parsing

util/face-options.hh

@@ -36,6 +36,9 @@ struct face_options_t
     g_free (font_file);
   }
 
+  void set_face (hb_face_t *face_)
+  { face = face_; }
+
   void add_options (option_parser_t *parser);
 
   void post_parse (GError **error);

util/hb-subset.cc

@@ -46,8 +46,37 @@ struct subset_main_t : option_parser_t, face_options_t, output_options_t<false>
     hb_subset_input_destroy (input);
   }
 
+  void parse_face (int argc, const char * const *argv)
+  {
+    option_parser_t parser;
+    face_options_t face_opts;
+
+    face_opts.add_options (&parser);
+
+    GOptionEntry entries[] =
+    {
+      {G_OPTION_REMAINING,	0, G_OPTION_FLAG_IN_MAIN,
+				G_OPTION_ARG_CALLBACK,	(gpointer) &collect_face,	nullptr,	"[FONT-FILE] [TEXT]"},
+      {nullptr}
+    };
+    parser.add_main_group (entries, &face_opts);
+
+    g_option_context_set_ignore_unknown_options (parser.context, true);
+    g_option_context_set_help_enabled (parser.context, false);
+
+    char **args = (char **) g_memdup (argv, argc * sizeof (*argv));
+    parser.parse (&argc, &args, true);
+    g_free (args);
+
+    set_face (face_opts.face);
+  }
+
   void parse (int argc, char **argv)
   {
+    /* Do a preliminary parse to load font-face, such that we can use it
+     * during main option parsing. */
+    parse_face (argc, argv);
+
     add_options ();
     option_parser_t::parse (&argc, &argv);
   }
@@ -103,6 +132,11 @@ struct subset_main_t : option_parser_t, face_options_t, output_options_t<false>
 
   protected:
   static gboolean
+  collect_face (const char *name,
+		const char *arg,
+		gpointer    data,
+		GError    **error);
+  static gboolean
   collect_rest (const char *name,
 		const char *arg,
 		gpointer    data,
@@ -565,6 +599,23 @@ parse_file_for (const char *name,
   return true;
 }
 
+gboolean
+subset_main_t::collect_face (const char *name,
+			     const char *arg,
+			     gpointer    data,
+			     GError    **error)
+{
+  face_options_t *thiz = (face_options_t *) data;
+
+  if (!thiz->font_file)
+  {
+    thiz->font_file = g_strdup (arg);
+    return true;
+  }
+
+  return true;
+}
+
 gboolean
 subset_main_t::collect_rest (const char *name,
 			     const char *arg,

util/options.hh

@@ -126,7 +126,8 @@ struct option_parser_t
     GOptionGroup *group = g_option_group_new (nullptr, nullptr, nullptr,
 					      static_cast<gpointer>(closure), nullptr);
     g_option_group_add_entries (group, entries);
-    g_option_group_set_parse_hooks (group, nullptr, post_parse<Type>);
+    /* https://gitlab.gnome.org/GNOME/glib/-/issues/2460 */
+    //g_option_group_set_parse_hooks (group, nullptr, post_parse<Type>);
     g_option_context_set_main_group (context, group);
   }
 
@@ -143,10 +144,10 @@ struct option_parser_t
     g_ptr_array_add (to_free, p);
   }
 
-  void parse (int *argc, char ***argv);
+  bool parse (int *argc, char ***argv, bool ignore_error = false);
 
-  protected:
   GOptionContext *context;
+  protected:
   GPtrArray *to_free;
 };
 
@@ -195,8 +196,8 @@ option_parser_t::add_options ()
   g_option_context_add_main_entries (context, entries, nullptr);
 }
 
-inline void
-option_parser_t::parse (int *argc, char ***argv)
+inline bool
+option_parser_t::parse (int *argc, char ***argv, bool ignore_error)
 {
   setlocale (LC_ALL, "");
 
@@ -205,12 +206,18 @@ option_parser_t::parse (int *argc, char ***argv)
   {
     if (parse_error)
     {
-      fail (true, "%s", parse_error->message);
-      //g_error_free (parse_error);
+      if (!ignore_error)
+	fail (true, "%s", parse_error->message);
+      g_error_free (parse_error);
     }
     else
-      fail (true, "Option parse error");
+    {
+      if (!ignore_error)
+	fail (true, "Option parse error");
+    }
+    return false;
   }
+  return true;
 }