1 files changed, 39 insertions, 0 deletions

diff --git a/lib/debug.h b/lib/debug.h
new file mode 100644
index 0000000..888ab7b
--- /dev/null
+++ b/lib/debug.h
@@ -0,0 +1,39 @@
+#ifndef __LIB_DEBUG_H
+#define __LIB_DEBUG_H
+
+/* GCC lets us add "attributes" to functions, function
+   parameters, etc. to indicate their properties.
+   See the GCC manual for details. */
+#define UNUSED __attribute__ ((unused))
+#define NO_RETURN __attribute__ ((noreturn))
+#define NO_INLINE __attribute__ ((noinline))
+#define PRINTF_FORMAT(FMT, FIRST) __attribute__ ((format (printf, FMT, FIRST)))
+
+/* Halts the OS, printing the source file name, line number, and
+   function name, plus a user-specific message. */
+#define PANIC(...) debug_panic (__FILE__, __LINE__, __func__, __VA_ARGS__)
+
+void debug_panic (const char *file, int line, const char *function,
+                  const char *message, ...) PRINTF_FORMAT (4, 5) NO_RETURN;
+void debug_backtrace (void);
+void debug_backtrace_all (void);
+
+#endif
+
+
+
+/* This is outside the header guard so that debug.h may be
+   included multiple times with different settings of NDEBUG. */
+#undef ASSERT
+#undef NOT_REACHED
+
+#ifndef NDEBUG
+#define ASSERT(CONDITION)                                       \
+        if (CONDITION) { } else {                               \
+                PANIC ("assertion `%s' failed.", #CONDITION);   \
+        }
+#define NOT_REACHED() PANIC ("executed an unreachable statement");
+#else
+#define ASSERT(CONDITION) ((void) 0)
+#define NOT_REACHED() for (;;)
+#endif /* lib/debug.h */