X-Git-Url: https://git.liburcu.org/?p=urcu.git;a=blobdiff_plain;f=urcu%2Fcompiler.h;h=511dbdf302456d46329bce98e1147b7c34a51543;hp=19534f08522ac3cc28a3557d93f7a16baab6e56e;hb=6a00c945d10d68e174c9fe96b2a98eb124b0d77e;hpb=4b5f005b03669c2942969e691fc3a0be47b15c57

diff --git a/urcu/compiler.h b/urcu/compiler.h
index 19534f0..511dbdf 100644
--- a/urcu/compiler.h
+++ b/urcu/compiler.h
@@ -64,6 +64,7 @@
  * @member: name of the field within the object.
  */
 #define caa_container_of(ptr, type, member)				\
+	__extension__							\
 	({								\
 		const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \
 		(type *)((char *)__ptr - offsetof(type, member));	\
@@ -89,16 +90,15 @@
 #define caa_is_signed_type(type)	((type) -1 < (type) 0)
 
 /*
- * Sign-extend to long if needed, and output type is unsigned long.
+ * Cast to unsigned long, sign-extending if @v is signed.
+ * Note: casting to a larger type or to same type size keeps the sign of
+ * the expression being cast (see C99 6.3.1.3).
  */
-#define caa_cast_long_keep_sign(v)		\
-	(caa_is_signed_type(__typeof__(v)) ?	\
-		(unsigned long) (long) (v) :	\
-		(unsigned long) (v))
+#define caa_cast_long_keep_sign(v)	((unsigned long) (v))
 
 #if defined (__GNUC__) \
-	&& ((__GNUC_MAJOR__ == 4) && (__GNUC_MINOR__ >= 5)	\
-		|| __GNUC_MAJOR__ >= 5)
+	&& ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 5)	\
+		|| __GNUC__ >= 5)
 #define CDS_DEPRECATED(msg)	\
 	__attribute__((deprecated(msg)))
 #else
@@ -108,4 +108,23 @@
 
 #define CAA_ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
 
+/*
+ * Don't allow compiling with buggy compiler.
+ */
+
+#ifdef __GNUC__
+# define URCU_GCC_VERSION	(__GNUC__ * 10000 \
+				+ __GNUC_MINOR__ * 100 \
+				+ __GNUC_PATCHLEVEL__)
+
+/*
+ * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58854
+ */
+# ifdef __ARMEL__
+#  if URCU_GCC_VERSION >= 40800 && URCU_GCC_VERSION <= 40802
+#   error Your gcc version produces clobbered frame accesses
+#  endif
+# endif
+#endif
+
 #endif /* _URCU_COMPILER_H */