gobject: Clean up logic in property checks

Simplify some of the logic in this function.

  1) Simplify flag checks as per Colin's suggestions in
     https://bugzilla.gnome.org/show_bug.cgi?id=605667

  2) Don't repeatedly recheck if class_pspec is NULL.

diff --git a/gobject/gobject.c b/gobject/gobject.c
index 59fcca2..c581839 100644 (file)
--- a/gobject/gobject.c
+++ b/gobject/gobject.c
@@ -1380,19 +1380,15 @@ object_interface_check_properties (gpointer func_data,
        * the READABLE and WRITABLE flags. We also simplify here
        * by only checking the value type, not the G_PARAM_SPEC_TYPE.
        */
-      if (class_pspec &&
-         !g_type_is_a (pspecs[n]->value_type,
-                       class_pspec->value_type))
-       {
-         g_critical ("Property '%s' on class '%s' has type '%s' "
-                     "which is different from the type '%s', "
-                     "of the property on interface '%s'\n",
-                     pspecs[n]->name,
-                     g_type_name (G_OBJECT_CLASS_TYPE (class)),
-                     g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
-                     g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])),
-                     g_type_name (iface_type));
-       }
+      if (g_type_is_a (pspecs[n]->value_type, class_pspec->value_type))
+        g_critical ("Property '%s' on class '%s' has type '%s' "
+                    "which is different from the type '%s', "
+                    "of the property on interface '%s'\n",
+                    pspecs[n]->name,
+                    g_type_name (G_OBJECT_CLASS_TYPE (class)),
+                    g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
+                    g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])),
+                    g_type_name (iface_type));
 
 #define SUBSET(a,b,mask) (((a) & ~(b) & (mask)) == 0)
 
@@ -1400,22 +1396,18 @@ object_interface_check_properties (gpointer func_data,
        * READABLE and WRITABLE remove restrictions. The implementation
        * paramspec must have less restrictive flags.
        */
-      if (class_pspec &&
-          (((pspecs[n]->flags & G_PARAM_WRITABLE) &&
-            !SUBSET (class_pspec->flags,
-                     pspecs[n]->flags,
-                     G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY)) ||
-          !SUBSET (pspecs[n]->flags,
-                   class_pspec->flags,
-                   G_PARAM_READABLE | G_PARAM_WRITABLE)))
-       {
-         g_critical ("Flags for property '%s' on class '%s' "
-                     "are not compatible with the property on"
-                     "interface '%s'\n",
-                     pspecs[n]->name,
-                     g_type_name (G_OBJECT_CLASS_TYPE (class)),
-                     g_type_name (iface_type));
-       }
+      if (pspecs[n]->flags & G_PARAM_WRITABLE)
+        {
+          if (!SUBSET (class_pspec->flags, pspecs[n]->flags, G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
+            g_critical ("Flags for property '%s' on class '%s' introduce additional restrictions on "
+                        "writability compared with the property on interface '%s'\n", pspecs[n]->name,
+                        g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (iface_type));
+        }
+
+      if (!SUBSET (pspecs[n]->flags, class_pspec->flags, G_PARAM_READABLE | G_PARAM_WRITABLE))
+        g_critical ("Flags for property '%s' on class '%s' remove functionality compared with the "
+                    "property on interface '%s'\n", pspecs[n]->name,
+                    g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (iface_type));
 #undef SUBSET
     }