X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=urcu%2Fcompiler.h;h=e7817dbd019f8803abea56cd54fd749ebe6279d6;hb=6488f70bcf96976bfda4d1836e0cab5ef6f599ff;hp=0c6ece252ca0e8bee2a480ab45588bb8ccd15bcd;hpb=e51500edbd9919cee53bc85cbb4b22cd4786fc42;p=urcu.git

diff --git a/urcu/compiler.h b/urcu/compiler.h
index 0c6ece2..e7817db 100644
--- a/urcu/compiler.h
+++ b/urcu/compiler.h
@@ -70,7 +70,7 @@
 	})
 
 #define CAA_BUILD_BUG_ON_ZERO(cond) (sizeof(struct { int:-!!(cond); }))
-#define CAA_BUILD_BUG_ON(cond) ((void)BUILD_BUG_ON_ZERO(cond))
+#define CAA_BUILD_BUG_ON(cond) ((void)CAA_BUILD_BUG_ON_ZERO(cond))
 
 /*
  * __rcu is an annotation that documents RCU pointer accesses that need
@@ -86,9 +86,32 @@
 #define URCU_FORCE_CAST(type, arg)	((type) (arg))
 #endif
 
-#define caa_is_signed_type(type)	(((type) (-1)) < 0)
+#define caa_is_signed_type(type)	((type) -1 < (type) 0)
 
-#define caa_cast_long_keep_sign(v)	\
-	(caa_is_signed_type(__typeof__(v)) ? (long) (v) : (unsigned long) (v))
+/*
+ * 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)	((unsigned long) (v))
+
+/*
+ * 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 */