Initial import of libucore

src/ucore_utils.h

@@ -0,0 +1,54 @@
+#ifndef UCORE_UTILS_H_
+#define UCORE_UTILS_H_
+#include <stddef.h>
+
+//Gnerate a compiler error if the compile time
+//constant expression fails
+#define STATIC_ASSERT(expr) \
+    do { \
+        enum { assert_static__ = 1/(expr) }; \
+    } while (0)
+
+#ifdef DEBUG
+    #define TRACEF(fmt, ...)\
+    do { \
+        fprintf(stderr, "%s:%s(%d)" fmt, __FILE__, __FUNCTION__, __LINE,__VA_ARGS__);\
+    } while(0)
+#else
+    #define TRACEF(fmt, ...)
+#endif
+
+//MAX of a and b
+#define UC_MAX(a,b) \
+   ({ __typeof__ (a) _a = (a); \
+       __typeof__ (b) _b = (b); \
+     _a > _b ? _a : _b; })
+
+//min of a and b
+#define UC_MIN(a,b) \
+   ({ __typeof__ (a) _a = (a); \
+       __typeof__ (b) _b = (b); \
+     _a < _b ? _a : _b; })
+
+#define ARRAY_SIZE(a) (sizeof(a) / sizeof(*a))
+
+//given 'ptr' as a pointer to a struct 'member',
+//find the struct that ptr is the member of, where
+//'type' is the type of the containing struct
+//e.g.
+//struct foo {
+//   int i;
+//   struct bar zap;
+//};
+// ... 
+//struct bar *p = ..; //the local p is a pointer to
+//a 'zap' member inside a struct foo.
+//give us the struct foo*:
+//struct foo *f = CONTAINER_OF(p, struct foo, zap);
+#define CONTAINER_OF(ptr, type, member) ({                  \
+const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
+    (type *)( (char *)__mptr - offsetof(type, member) ); })
+
+
+#endif
+