[Spice-devel] [spice-protocol PATCH v2 01/10] macros: verify if __alloc_size__ works with clang

[Victor Toso]

So we can avoid using using an attribute not supported for the compiler.

warning:
../spice-common/common/mem.h:91:80: warning: unknown attribute
'__alloc_size__' ignored [-Wunknown-attributes]

void *spice_malloc0_n(size_t n_blocks, size_t n_block_bytes)
SPICE_GNUC_MALLOC SPICE_GNUC_ALLOC_SIZE2(1,2);

../spice-common/spice-protocol/spice/macros.h:52:52: note: expanded
from macro 'SPICE_GNUC_ALLOC_SIZE2'

 #define SPICE_GNUC_ALLOC_SIZE2(x,y) __attribute__((__alloc_size__(x,y)))
                                                    ^
---
 spice/macros.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/spice/macros.h b/spice/macros.h
index 716f6e0..c4f2625 100644
--- a/spice/macros.h
+++ b/spice/macros.h
@@ -47,7 +47,8 @@
 #define SPICE_GNUC_NULL_TERMINATED
 #endif
 
-#if     (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3)
+#if     (!defined(__clang__) && ((__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 3))) || \
+        (defined(__clang__) && __has_feature(__alloc_size__))
 #define SPICE_GNUC_ALLOC_SIZE(x) __attribute__((__alloc_size__(x)))
 #define SPICE_GNUC_ALLOC_SIZE2(x,y) __attribute__((__alloc_size__(x,y)))
 #else
-- 
2.4.3