Annotate varargs functions with G_GNUC_PRINTF

This lets the compiler detect and diagnose type mismatches like the one
fixed in the previous commit.

Helps: https://gitlab.freedesktop.org/accountsservice/accountsservice/-/issues/109
Signed-off-by: Simon McVittie <smcv@debian.org>

3 files changed, 11 insertions, 1 deletions

diff --git a/src/daemon.c b/src/daemon.c
index 81bf5ad..0fbd1d7 100644
--- a/src/daemon.c
+++ b/src/daemon.c
@@ -876,6 +876,11 @@ daemon_new (void)
         return g_steal_pointer (&daemon);
 }
 
+static void throw_error (GDBusMethodInvocation *context,
+                         gint                   error_code,
+                         const gchar           *format,
+                         ...) G_GNUC_PRINTF (3, 4);
+
 static void
 throw_error (GDBusMethodInvocation *context,
              gint                   error_code,
diff --git a/src/user.c b/src/user.c
index 67cbb1b..0a8e586 100644
--- a/src/user.c
+++ b/src/user.c
@@ -1120,6 +1120,11 @@ user_set_saved (User    *user,
         accounts_user_set_saved (ACCOUNTS_USER (user), saved);
 }
 
+static void throw_error (GDBusMethodInvocation *context,
+                         gint                   error_code,
+                         const gchar           *format,
+                         ...) G_GNUC_PRINTF (3, 4);
+
 static void
 throw_error (GDBusMethodInvocation *context,
              gint                   error_code,
diff --git a/src/util.h b/src/util.h
index d2cd6ed..c8a4a2d 100644
--- a/src/util.h
+++ b/src/util.h
@@ -25,7 +25,7 @@
 
 void sys_log (GDBusMethodInvocation *context,
               const gchar           *format,
-              ...);
+              ...) G_GNUC_PRINTF (2, 3);
 
 gboolean get_caller_uid (GDBusMethodInvocation *context,
                          gint                  *uid);