gsignal: Add support for G_CONNECT_SWAPPED

It was mysteriously missing before, because it is actually a hard
problem than it looks to check correctly. This adds support for
g_signal_connect_swapped() and g_signal_connect_data() with the
G_CONNECT_SWAPPED flag.

Currently, the user_data parameter is validated as being any kind of
pointer. This could potentially be tightened up in future to check that
it is a subtype of the closure variable passed into g_signal_connect()
(even in the non-G_CONNECT_SWAPPED case). However, this is best left to
a separate checker which examines closure types.

2 files changed, 102 insertions, 0 deletions

diff --git a/tests/gsignal-connect.c b/tests/gsignal-connect.c
index 6d34bd6..f60520a 100644
--- a/tests/gsignal-connect.c
+++ b/tests/gsignal-connect.c
@@ -196,3 +196,91 @@
 	g_signal_connect (settings, "changed",
 	                  (GCallback) settings_changed_const_cb, NULL);
 }
+
+/*
+ * No error
+ */
+{
+	GSettings *settings = g_malloc (5);  // only checking the type
+	g_signal_connect_swapped (settings, "changed",
+	                          (GCallback) settings_changed_swapped_cb,
+	                          NULL);
+}
+
+/*
+ * No error
+ */
+{
+	GSettings *settings = g_malloc (5);  // only checking the type
+	gint some_thing[] = { 0, 1, 2 }; // subtype of gpointer, so valid
+	g_signal_connect_swapped (settings, "changed",
+	                          (GCallback) settings_changed_swapped_cb,
+	                          some_thing);
+}
+
+/*
+ * No error
+ */
+{
+	GSettings *settings = g_malloc (5);  // only checking the type
+	gint some_thing[] = { 0, 1, 2 }; // subtype of gpointer, so valid
+	g_signal_connect_swapped (settings, "changed",
+	                          (GCallback) settings_changed_swapped_cb,
+	                          some_thing);
+}
+
+/*
+ * No error
+ */
+{
+	GSettings *settings = g_malloc (5);  // only checking the type
+	gint some_thing[] = { 0, 1, 2 }; // not a GInputStream; FIXME: might be marked as invalid in future
+	g_signal_connect_swapped (settings, "changed",
+	                          (GCallback) settings_changed_swapped_stream_cb,
+	                          some_thing);
+}
+
+/*
+ * No error
+ */
+{
+	GSettings *settings = g_malloc (5);  // only checking the type
+	GFilterInputStream *stream = g_malloc (5);  // GInputStream subtype; valid
+	g_signal_connect_swapped (settings, "changed",
+	                          (GCallback) settings_changed_swapped_stream_cb,
+	                          stream);
+}
+
+/*
+ * No error
+ */
+{
+	GSettings *settings = g_malloc (5);  // only checking the type
+	GObject *stream = g_malloc (5);  // GInputStream supertype; FIXME: might be marked as invalid in future
+	g_signal_connect_swapped (settings, "changed",
+	                          (GCallback) settings_changed_swapped_stream_cb,
+	                          stream);
+}
+
+/*
+ * No error
+ */
+{
+	GSettings *settings = g_malloc (5);  // only checking the type
+	gint some_thing[] = { 0, 1, 2 }; // subtype of gpointer, so valid
+	g_signal_connect_data (settings, "changed",
+	                       (GCallback) settings_changed_swapped_cb,
+	                       some_thing, NULL, G_CONNECT_SWAPPED);
+}
+
+/*
+ * No error
+ */
+{
+	GSettings *settings = g_malloc (5);  // only checking the type
+	gint some_thing[] = { 0, 1, 2 }; // subtype of gpointer, so valid
+	g_signal_connect_data (settings, "changed",
+	                       (GCallback) settings_changed_swapped_cb,
+	                       some_thing, NULL,
+	                       G_CONNECT_SWAPPED | G_CONNECT_AFTER);
+}
diff --git a/tests/gsignal.head.c b/tests/gsignal.head.c
index e4f3026..f651e4f 100644
--- a/tests/gsignal.head.c
+++ b/tests/gsignal.head.c
@@ -90,6 +90,20 @@ settings_changed_const_cb (GSettings *settings, const gchar *key,
 	/* Something */
 }
 
+static void
+settings_changed_swapped_cb (gpointer user_data, const gchar *key,
+                             GSettings *settings)
+{
+	/* Something */
+}
+
+static void
+settings_changed_swapped_stream_cb (GInputStream *stream, const gchar *key,
+                                    GSettings *settings)
+{
+	/* Something */
+}
+
 int
 main (void)
 {