BUILD: debug: make sure debug macros are never empty
As outlined in commit f7ebe584d7 ("BUILD: debug: Add braces to if
statement calling only CHECK_IF()"), the BUG_ON() family of macros
is incorrectly defined to be empty when debugging is disabled, and
that can lead to trouble. Make sure they always fall back to the
usual "do { } while (0)". This may be backported to 2.6 if needed,
though no such issue was met there to date.
diff --git a/include/haproxy/bug.h b/include/haproxy/bug.h
index d65c156..60b2467 100644
--- a/include/haproxy/bug.h
+++ b/include/haproxy/bug.h
@@ -140,9 +140,9 @@
# define CHECK_IF(cond) _BUG_ON_ONCE(cond, __FILE__, __LINE__, 1, "FATAL: check ", "")
# endif
#else
-# define BUG_ON(cond)
-# define WARN_ON(cond)
-# define CHECK_IF(cond)
+# define BUG_ON(cond) do { } while (0)
+# define WARN_ON(cond) do { } while (0)
+# define CHECK_IF(cond) do { } while (0)
#endif
/* These macros are only for hot paths and remain disabled unless DEBUG_STRICT is 2 or above.
@@ -164,8 +164,8 @@
# define CHECK_IF_HOT(cond) _BUG_ON_ONCE(cond, __FILE__, __LINE__, 1, "FATAL: check ", "")
# endif
#else
-# define BUG_ON_HOT(cond)
-# define CHECK_IF_HOT(cond)
+# define BUG_ON_HOT(cond) do { } while (0)
+# define CHECK_IF_HOT(cond) do { } while (0)
#endif