Add helper to print warnings once

The helper is general, although in this patch it is only used for
warnings. No functional change intended.

1 files changed, 5 insertions, 8 deletions

diff --git a/mesonbuild/modules/i18n.py b/mesonbuild/modules/i18n.py
index 1efc7b5..80ec8bd 100644
--- a/mesonbuild/modules/i18n.py
+++ b/mesonbuild/modules/i18n.py
@@ -16,7 +16,7 @@ import shutil
 
 from os import path
 from .. import coredata, mesonlib, build, mlog
-from ..mesonlib import MesonException
+from ..mesonlib import MesonException, run_once
 from . import ModuleReturnValue
 from . import ExtensionModule
 from ..interpreterbase import permittedKwargs, FeatureNew, FeatureNewKwargs
@@ -58,13 +58,10 @@ PRESET_ARGS = {
 
 class I18nModule(ExtensionModule):
 
-    nogettext_warning_printed = False
-
-    @classmethod
-    def nogettext_warning(cls):
-        if not cls.nogettext_warning_printed:
-            mlog.warning('Gettext not found, all translation targets will be ignored.')
-            cls.nogettext_warning_printed = True
+    @staticmethod
+    @run_once
+    def nogettext_warning():
+        mlog.warning('Gettext not found, all translation targets will be ignored.')
         return ModuleReturnValue(None, [])
 
     @staticmethod