better implementation of WARN

diff --git a/include/linux/bug.h b/include/linux/bug.h
index f8929688cfd9d5855bda42bbed9a86b1e48fddbe..a64a309c81a11f74f60ef2d57c9b83c751f5203c 100644 (file)
--- a/include/linux/bug.h
+++ b/include/linux/bug.h
@@ -9,22 +9,46 @@
 #define BUILD_BUG_ON_ZERO(e)   (sizeof(struct { int:-!!(e); }))
 #define BUILD_BUG_ON_NULL(e)   ((void *)sizeof(struct { int:-!!(e); }))
 
-#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
+#define BUILD_BUG_ON(cond)     ((void)sizeof(char[1 - 2*!!(cond)]))
 
 #define BUG()                  do { assert(0); unreachable(); } while (0)
 #define BUG_ON(cond)           assert(!(cond))
 
-#define WARN_ON_ONCE(cond)     ({ bool _r = (cond); if (_r) assert(0); _r; })
-#define WARN_ONCE(cond, ...)   ({ bool _r = (cond); if (_r) assert(0); _r; })
-
-#define __WARN()               assert(0)
-#define __WARN_printf(arg...)  assert(0)
-#define WARN(cond, ...)                assert(!(cond))
+#define WARN(cond, fmt, ...)                                           \
+({                                                                     \
+       int __ret_warn_on = unlikely(!!(cond));                         \
+       if (__ret_warn_on)                                              \
+               fprintf(stderr, "WARNING at " __FILE__ ":%d: " fmt "\n",\
+                       __LINE__, ##__VA_ARGS__);                       \
+       __ret_warn_on;                                                  \
+})
 
-#define WARN_ON(condition) ({                                          \
-       int __ret_warn_on = unlikely(!!(condition));                    \
+#define WARN_ON(cond) ({                                               \
+       int __ret_warn_on = unlikely(!!(cond));                         \
        if (__ret_warn_on)                                              \
-               __WARN();                                               \
+               fprintf(stderr, "WARNING at " __FILE__ ":%d\n", __LINE__);\
+       __ret_warn_on;                                                  \
+})
+
+#define WARN_ONCE(cond, fmt, ...)                                      \
+({                                                                     \
+       static bool __warned;                                           \
+       int __ret_warn_on = unlikely(!!(cond));                         \
+       if (__ret_warn_on && !__warned) {                               \
+               __warned = true;                                        \
+               fprintf(stderr, "WARNING at " __FILE__ ":%d: " fmt "\n",\
+                       __LINE__, ##__VA_ARGS__);                       \
+       }                                                               \
+       __ret_warn_on;                                                  \
+})
+
+#define WARN_ON_ONCE(cond) ({                                          \
+       static bool __warned;                                           \
+       int __ret_warn_on = unlikely(!!(cond));                         \
+       if (__ret_warn_on && !__warned) {                               \
+               __warned = true;                                        \
+               fprintf(stderr, "WARNING at " __FILE__ ":%d\n", __LINE__);\
+       }                                                               \
        __ret_warn_on;                                                  \
 })