[Spice-devel] [PATCH v2] macros: do not use more type safe CONTAINEROF version if not requested

[Frediano Ziglio]

This prevents incompatibility if users (like old spice-server/spice-gtk)
are not expected to have this additional restriction.

Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
---
 spice/macros.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Changes since v1:
- macro name;
- added code comment.

diff --git a/spice/macros.h b/spice/macros.h
index 2efbaff..a0413f3 100644
--- a/spice/macros.h
+++ b/spice/macros.h
@@ -143,7 +143,12 @@
     ((long) ((uint8_t*) &((struct_type*) 0)->member))
 #endif
 
-#if    __GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4)
+/* The SPICE_USE_SAFER_CONTAINEROF macro is used to avoid
+ * compilation breakage with older spice-server releases which
+ * triggered some errors without an additional patch.
+ */
+#if defined(__GNUC__) && defined(SPICE_USE_SAFER_CONTAINEROF) && \
+    (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4))
 #define SPICE_CONTAINEROF(ptr, struct_type, member) ({ \
     const typeof( ((struct_type *)0)->member ) *__mptr = (ptr);    \
     ((struct_type *)(void *)((uint8_t *)(__mptr) - SPICE_OFFSETOF(struct_type, member))); })
-- 
2.5.0