From 9458f991eb90b4cfef3836dd37ae6d1fe96409fd Mon Sep 17 00:00:00 2001
From: nikita <nikita>
Date: Fri, 8 Aug 2008 13:44:30 +0000
Subject: [PATCH] lassert: 0. add LINVRNT() macro for more expensive checks
 that are disabled by default; 1. replace ((void)0) with ((void)!!sizeof(exp))
 so that expression is used (though not evaluated) even when assertions are
 disabled. !! is for things --like bitfields-- that do not have sizeof.

---
 libcfs/include/libcfs/libcfs_private.h | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/libcfs/include/libcfs/libcfs_private.h b/libcfs/include/libcfs/libcfs_private.h
index e0a27a9..3620355 100644
--- a/libcfs/include/libcfs/libcfs_private.h
+++ b/libcfs/include/libcfs/libcfs_private.h
@@ -116,13 +116,23 @@
 
 
 #endif /* !LASSERT_CHECKED */
-
-
 #else /* !LIBCFS_DEBUG */
-#define LASSERT(e) ((void)(0))
-#define LASSERTF(cond, fmt...) ((void)(0))
+/* sizeof is to use expression without evaluating it. */
+# define LASSERT(e) ((void)sizeof!!(e))
+# define LASSERTF(cond, fmt...) ((void)sizeof!!(cond))
 #endif /* !LIBCFS_DEBUG */
 
+#ifdef INVARIANT_CHECK
+/**
+ * This is for more expensive checks that one doesn't want to be enabled all
+ * the time. LINVRNT() has to be explicitly enabled by --enable-invariants
+ * configure option.
+ */
+# define LINVRNT(exp) LASSERT(exp)
+#else
+# define LINVRNT(exp) ((void)sizeof!!(exp))
+#endif
+
 #define KLASSERT(e) LASSERT(e)
 
 void lbug_with_loc(char *file, const char *func, const int line)
@@ -234,12 +244,18 @@ do {                                                                           \
           assert(cond);                                                        \
 } while (0)
 #  define LBUG()   assert(0)
+#  ifdef INVARIANT_CHECK
+#   define LINVRNT(exp) LASSERT(exp)
+#  else
+#   define LINVRNT(exp) ((void)sizeof!!(exp))
+#  endif
 # else
-#  define LASSERT(e) ((void)(0))
-#  define LASSERTF(cond, args...) do { } while (0)
+#  define LASSERT(e) ((void)sizeof!!(e))
+#  define LASSERTF(cond, args...) ((void)sizeof!!(cond))
 #  define LBUG()   ((void)(0))
+#  define LINVRNT(exp) ((void)sizeof!!(exp))
 # endif /* LIBCFS_DEBUG */
-# define KLASSERT(e) do { } while (0)
+# define KLASSERT(e) ((void)0)
 # define printk(format, args...) printf (format, ## args)
 # ifdef CRAY_XT3                                /* buggy calloc! */
 #  define LIBCFS_ALLOC(ptr, size)               \
-- 
1.8.3.1