[PATCH] Make WARN_ON/WARN_ON_ONCE no-ops when CONFIG_BUG is off

From: Herbert Xu
Date: Fri Dec 14 2007 - 08:28:15 EST


Hi:

[PATCH] Make WARN_ON/WARN_ON_ONCE no-ops when CONFIG_BUG is off

The description of CONFIG_BUG clearly states that both BUG and
WARN_ON may be skipped. However, our actual implementation still
checks the condition on WARN_ON if it's used as part of an if
statement or such.

This patch makes it return 0 after evaluating the expression
if CONFIG_BUG is disabled. This is consistent with the spirit
of the CONFIG_BUG option.

The same change is made to WARN_ON_ONCE.

Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>

Thanks,
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Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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--
diff --git a/include/asm-generic/bug.h b/include/asm-generic/bug.h
index d56fedb..3e74278 100644
--- a/include/asm-generic/bug.h
+++ b/include/asm-generic/bug.h
@@ -43,6 +43,16 @@ struct bug_entry {
})
#endif

+#define WARN_ON_ONCE(condition) ({ \
+ static int __warned; \
+ int __ret_warn_once = !!(condition); \
+ \
+ if (unlikely(__ret_warn_once)) \
+ if (WARN_ON(!__warned)) \
+ __warned = 1; \
+ unlikely(__ret_warn_once); \
+})
+
#else /* !CONFIG_BUG */
#ifndef HAVE_ARCH_BUG
#define BUG()
@@ -53,22 +63,11 @@ struct bug_entry {
#endif

#ifndef HAVE_ARCH_WARN_ON
-#define WARN_ON(condition) ({ \
- int __ret_warn_on = !!(condition); \
- unlikely(__ret_warn_on); \
-})
-#endif
+#define WARN_ON(condition) ((condition), 0)
#endif

-#define WARN_ON_ONCE(condition) ({ \
- static int __warned; \
- int __ret_warn_once = !!(condition); \
- \
- if (unlikely(__ret_warn_once)) \
- if (WARN_ON(!__warned)) \
- __warned = 1; \
- unlikely(__ret_warn_once); \
-})
+#define WARN_ON_ONCE(condition) ((condition), 0)
+#endif

#ifdef CONFIG_SMP
# define WARN_ON_SMP(x) WARN_ON(x)
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