util: Introduce ovs_assert macro.

An occasionally significant problem with the standard "assert" macro is
that it writes the failure message to stderr.  In our daemons, stderr is
generally redirected to /dev/null.  It's more useful to write the failure
message to the log, which is what the new ovs_assert macro introduced in
this patch does.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/lib/util.h b/lib/util.h
index 70f36919..b944ec79 100644
--- a/lib/util.h
+++ b/lib/util.h
@@ -62,6 +62,17 @@
 #define BUILD_ASSERT_DECL_GCCONLY(EXPR) ((void) 0)
 #endif
 
+/* Like the standard assert macro, except:
+ *
+ *   - Writes the failure message to the log.
+ *
+ *   - Not affected by NDEBUG. */
+#define ovs_assert(CONDITION)                                           \
+    if (!OVS_LIKELY(CONDITION)) {                                       \
+        ovs_assert_failure(SOURCE_LOCATOR, __func__, #CONDITION);       \
+    }
+void ovs_assert_failure(const char *, const char *, const char *) NO_RETURN;
+
 /* Casts 'pointer' to 'type' and issues a compiler warning if the cast changes
  * anything other than an outermost "const" or "volatile" qualifier.
  *