shared: propagate constness in _NM_GET_PRIVATE_PTR()

The _NM_GET_PRIVATE() macro already preserved and propagated
the constness of @self to the resulting private pointer.

_NM_GET_PRIVATE_PTR() didn't do that. Extend the macro,
to make that possible.

3 files changed, 31 insertions, 5 deletions

diff --git a/shared/nm-utils/nm-macros-internal.h b/shared/nm-utils/nm-macros-internal.h
index 515e8b5c3e..49bc79e582 100644
--- a/shared/nm-utils/nm-macros-internal.h
+++ b/shared/nm-utils/nm-macros-internal.h
@@ -263,6 +263,13 @@ NM_G_ERROR_MSG (GError *error)
 
 /*****************************************************************************/
 
+#if (defined (__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9 )))
+#define _NM_CC_SUPPORT_AUTO_TYPE 1
+#define _nm_auto_type __auto_type
+#else
+#define _NM_CC_SUPPORT_AUTO_TYPE 0
+#endif
+
 #if (defined (__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9 ))) || (defined (__clang__))
 #define _NM_CC_SUPPORT_GENERIC 1
 #else
@@ -372,6 +379,16 @@ NM_G_ERROR_MSG (GError *error)
 #define _NM_ENSURE_TYPE(type, value) (value)
 #endif
 
+#if _NM_CC_SUPPORT_GENERIC
+#define NM_PROPAGATE_CONST(test_expr, ptr) \
+	(_Generic ((test_expr), \
+	           const typeof (*(test_expr)) *: ((const typeof (*(ptr)) *) (ptr)), \
+	                                 default: (_Generic ((test_expr), \
+	                                                     typeof (*(test_expr)) *: (ptr)))))
+#else
+#define NM_PROPAGATE_CONST(test_expr, ptr) (ptr)
+#endif
+
 /*****************************************************************************/
 
 #define _NM_IN_SET_EVAL_1( op, _x, y)           (_x == (y))
@@ -651,8 +668,17 @@ _notify (obj_type *obj, _PropertyEnums prop) \
 
 /*****************************************************************************/
 
-#define _NM_GET_PRIVATE(     self, type, is_check, ...)     (&(NM_GOBJECT_CAST_NON_NULL (type, (self), is_check, ##__VA_ARGS__)->_priv))
-#define _NM_GET_PRIVATE_PTR( self, type, is_check, ...)     ( (NM_GOBJECT_CAST_NON_NULL (type, (self), is_check, ##__VA_ARGS__)->_priv))
+#define _NM_GET_PRIVATE(self, type, is_check, ...) (&(NM_GOBJECT_CAST_NON_NULL (type, (self), is_check, ##__VA_ARGS__)->_priv))
+#if _NM_CC_SUPPORT_AUTO_TYPE
+#define _NM_GET_PRIVATE_PTR(self, type, is_check, ...) \
+	({ \
+		_nm_auto_type _self = NM_GOBJECT_CAST_NON_NULL (type, (self), is_check, ##__VA_ARGS__); \
+		\
+		NM_PROPAGATE_CONST (_self, _self->_priv); \
+	})
+#else
+#define _NM_GET_PRIVATE_PTR(self, type, is_check, ...) (NM_GOBJECT_CAST_NON_NULL (type, (self), is_check, ##__VA_ARGS__)->_priv)
+#endif
 
 /*****************************************************************************/
 
diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index 010172dc06..1fe6f064da 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -1164,9 +1164,9 @@ nm_device_get_ip_iface (NMDevice *self)
 }
 
 int
-nm_device_get_ip_ifindex (NMDevice *self)
+nm_device_get_ip_ifindex (const NMDevice *self)
 {
-	NMDevicePrivate *priv;
+	const NMDevicePrivate *priv;
 
 	g_return_val_if_fail (self != NULL, 0);
 
diff --git a/src/devices/nm-device.h b/src/devices/nm-device.h
index bd8104b4bf..b0d299e4ea 100644
--- a/src/devices/nm-device.h
+++ b/src/devices/nm-device.h
@@ -438,7 +438,7 @@ int             nm_device_get_ifindex           (NMDevice *dev);
 gboolean        nm_device_is_software           (NMDevice *dev);
 gboolean        nm_device_is_real               (NMDevice *dev);
 const char *    nm_device_get_ip_iface          (NMDevice *dev);
-int             nm_device_get_ip_ifindex        (NMDevice *dev);
+int             nm_device_get_ip_ifindex        (const NMDevice *dev);
 const char *    nm_device_get_driver            (NMDevice *dev);
 const char *    nm_device_get_driver_version    (NMDevice *dev);
 const char *    nm_device_get_type_desc         (NMDevice *dev);