[virt-tools-list] [virt-viewer PATCH 2/5] Annotate message dialog helpers with format(gnu_printf)

[Daniel P. Berrangé]

This allows the compiler to validate the format string and args passed
to the function.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 src/virt-viewer-app.c      | 38 +++++++++++++++++++++++---------------
 src/virt-viewer-notebook.c |  4 ++--
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/src/virt-viewer-app.c b/src/virt-viewer-app.c
index fd48014..03a7c00 100644
--- a/src/virt-viewer-app.c
+++ b/src/virt-viewer-app.c
@@ -197,19 +197,16 @@ virt_viewer_app_set_debug(gboolean debug)
     doDebug = debug;
 }
 
-static GtkWidget*
-virt_viewer_app_make_message_dialog(VirtViewerApp *self,
-                                    const char *fmt, ...)
+__attribute__((format(gnu_printf, 2, 0))) static GtkWidget*
+virt_viewer_app_make_message_dialogv(VirtViewerApp *self,
+                                     const char *fmt, va_list vargs)
 {
     g_return_val_if_fail(VIRT_VIEWER_IS_APP(self), NULL);
     GtkWindow *window = GTK_WINDOW(virt_viewer_window_get_window(self->priv->main_window));
     GtkWidget *dialog;
     char *msg;
-    va_list vargs;
 
-    va_start(vargs, fmt);
     msg = g_strdup_vprintf(fmt, vargs);
-    va_end(vargs);
 
     dialog = gtk_message_dialog_new(window,
                                     GTK_DIALOG_MODAL |
@@ -224,23 +221,34 @@ virt_viewer_app_make_message_dialog(VirtViewerApp *self,
     return dialog;
 }
 
-void
+__attribute__((format(gnu_printf, 2, 3))) static GtkWidget*
+virt_viewer_app_make_message_dialog(VirtViewerApp *self,
+                                    const char *fmt, ...)
+{
+    g_return_val_if_fail(VIRT_VIEWER_IS_APP(self), NULL);
+    GtkWidget *dialog;
+    va_list vargs;
+
+    va_start(vargs, fmt);
+    dialog = virt_viewer_app_make_message_dialogv(self, fmt, vargs);
+    va_end(vargs);
+
+    return dialog;
+}
+
+__attribute__((format(gnu_printf, 2, 3))) void
 virt_viewer_app_simple_message_dialog(VirtViewerApp *self,
                                       const char *fmt, ...)
 {
     GtkWidget *dialog;
-    char *msg;
     va_list vargs;
 
     va_start(vargs, fmt);
-    msg = g_strdup_vprintf(fmt, vargs);
+    dialog = virt_viewer_app_make_message_dialogv(self, fmt, vargs);
     va_end(vargs);
 
-    dialog = virt_viewer_app_make_message_dialog(self, msg);
     gtk_dialog_run(GTK_DIALOG(dialog));
     gtk_widget_destroy(dialog);
-
-    g_free(msg);
 }
 
 static void
@@ -668,7 +676,7 @@ virt_viewer_app_open_unix_sock(const char *unixsock, GError **error)
 
 #endif /* defined(HAVE_SOCKETPAIR) && defined(HAVE_FORK) */
 
-void
+__attribute__((format(gnu_printf, 2, 3))) void
 virt_viewer_app_trace(VirtViewerApp *self,
                       const char *fmt, ...)
 {
@@ -1871,7 +1879,7 @@ virt_viewer_app_on_application_startup(GApplication *app)
 
     if (!virt_viewer_app_start(self, &error)) {
         if (error && !g_error_matches(error, VIRT_VIEWER_ERROR, VIRT_VIEWER_ERROR_CANCELLED))
-            virt_viewer_app_simple_message_dialog(self, error->message);
+            virt_viewer_app_simple_message_dialog(self, "%s", error->message);
 
         g_clear_error(&error);
         g_application_quit(app);
@@ -2477,7 +2485,7 @@ show_status_cb(gpointer value,
     virt_viewer_notebook_show_status(nb, text);
 }
 
-void
+__attribute__((format(gnu_printf, 2, 3))) void
 virt_viewer_app_show_status(VirtViewerApp *self, const gchar *fmt, ...)
 {
     va_list args;
diff --git a/src/virt-viewer-notebook.c b/src/virt-viewer-notebook.c
index 3a74e9f..a2092d2 100644
--- a/src/virt-viewer-notebook.c
+++ b/src/virt-viewer-notebook.c
@@ -82,7 +82,7 @@ virt_viewer_notebook_init (VirtViewerNotebook *self)
     gtk_notebook_append_page(GTK_NOTEBOOK(self), priv->status, NULL);
 }
 
-void
+__attribute__((format(gnu_printf, 2, 0))) void
 virt_viewer_notebook_show_status_va(VirtViewerNotebook *self, const gchar *fmt, va_list args)
 {
     VirtViewerNotebookPrivate *priv;
@@ -99,7 +99,7 @@ virt_viewer_notebook_show_status_va(VirtViewerNotebook *self, const gchar *fmt,
     g_free(text);
 }
 
-void
+__attribute__((format(gnu_printf, 2, 3))) void
 virt_viewer_notebook_show_status(VirtViewerNotebook *self, const gchar *fmt, ...)
 {
     va_list args;
-- 
2.20.1