compiler: Protect against redefinition of offsetof()

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 6 insertions, 4 deletions

diff --git a/compiler.h b/compiler.h
index 0921edd..a6bf3a6 100644
--- a/compiler.h
+++ b/compiler.h
@@ -20,10 +20,12 @@
 #define COMPILER_H
 
 #ifdef __GNUC__
-# define __noreturn	__attribute__((noreturn))
-# define __packed	__attribute__((packed))
-# define __unused	__attribute__((unused))
-# define offsetof(a, b)	__builtin_offsetof(a, b)
+# define __noreturn		__attribute__((noreturn))
+# define __packed		__attribute__((packed))
+# define __unused		__attribute__((unused))
+# ifndef offsetof
+#  define offsetof(a, b)	__builtin_offsetof(a, b)
+# endif
 #else
 # define __noreturn
 # define __packed