move BUG_ON, panic and kprintf define to debug.h; add BUILD_BUG_ON

these functions are more logical to keep together there as they depend
on each other.

Also add a comment about the __printf attribute, if we have a quiet
period it would be useful to enable and clear the thousands of
warnings...

Change-Id: I47d3891c9cd87da28b2883c29384959f5abd1459

kernel/include/debug.h

@@ -1,7 +1,12 @@
 #ifndef DEBUG_H
 #define DEBUG_H
 
-#include <lwk/compiler.h>
+#include "lwk/compiler.h"
+
+void panic(const char *);
+
+/* when someone has a lot of time, add attribute __printf(1, 2) to kprintf */
+int kprintf(const char *format, ...);
 
 struct ddebug {
 	const char *file;
@@ -37,4 +42,13 @@ do {                                  \
 } while (0)
 #define ekprintf(fmt, args...) kprintf(fmt, ##args)
 
+#define BUG_ON(condition) do {                         \
+	if (condition) {                               \
+		kprintf("PANIC: %s: %s(line:%d)\n",    \
+			__FILE__, __func__, __LINE__); \
+		panic("");                             \
+	}                                              \
+} while (0)
+#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
+
 #endif

kernel/include/kmalloc.h

@@ -13,11 +13,9 @@
 #ifndef __HEADER_KMALLOC_H
 #define __HEADER_KMALLOC_H
 
-#include <ihk/mm.h>
-#include <cls.h>
-
-void panic(const char *);
-int kprintf(const char *format, ...);
+#include "ihk/mm.h"
+#include "cls.h"
+#include "debug.h"
 
 #define kmalloc(size, flag) ({\
 void *r = _kmalloc(size, flag, __FILE__, __LINE__);\