Commit 684f9783 authored by Herbert Xu's avatar Herbert Xu Committed by Linus Torvalds
Browse files

[PATCH] Let WARN_ON/WARN_ON_ONCE return the condition 



Letting WARN_ON/WARN_ON_ONCE return the condition means that you could do

if (WARN_ON(blah)) {
	handle_impossible_case
}

Rather than

if (unlikely(blah)) {
	WARN_ON(1)
	handle_impossible_case
}

I checked all the newly added WARN_ON_ONCE users and none of them test the
return status so we can still change it.

[akpm@osdl.org: warning fix]
[akpm@osdl.org: build fix]
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 6299a2de

include/asm-generic/bug.h

+16 −16
Original line number Diff line number Diff line
@@ -16,12 +16,15 @@ 
#endif



#ifndef HAVE_ARCH_WARN_ON

#define WARN_ON(condition) do { \

	if (unlikely((condition)!=0)) { \

		printk("BUG: warning at %s:%d/%s()\n", __FILE__, __LINE__, __FUNCTION__); \

#define WARN_ON(condition) ({						\

	typeof(condition) __ret_warn_on = (condition);			\

	if (unlikely(__ret_warn_on)) {					\

		printk("BUG: warning at %s:%d/%s()\n", __FILE__,	\

			__LINE__, __FUNCTION__);			\

		dump_stack();						\

	}								\

} while (0)

	unlikely(__ret_warn_on);					\

})

#endif



#else /* !CONFIG_BUG */
@@ -34,21 +37,18 @@ 
#endif



#ifndef HAVE_ARCH_WARN_ON

#define WARN_ON(condition) do { if (condition) ; } while(0)

#define WARN_ON(condition) unlikely((condition))

#endif

#endif



#define WARN_ON_ONCE(condition)				\

({							\

#define WARN_ON_ONCE(condition)	({			\

	static int __warn_once = 1;			\

	int __ret = 0;					\

	typeof(condition) __ret_warn_once = (condition);\

							\

	if (unlikely((condition) && __warn_once)) {	\

	if (likely(__warn_once))			\

		if (WARN_ON(__ret_warn_once)) 		\

			__warn_once = 0;		\

		WARN_ON(1);				\

		__ret = 1;				\

	}						\

	__ret;						\

	unlikely(__ret_warn_once);			\

})



#ifdef CONFIG_SMP

include/asm-powerpc/bug.h

+7 −5
Original line number Diff line number Diff line
@@ -70,9 +70,10 @@ struct bug_entry *find_bug(unsigned long bugaddr); 
		    "i" (__FILE__), "i" (__FUNCTION__));	\

} while (0)



#define WARN_ON(x) do {						\

	if (__builtin_constant_p(x)) {				\

		if (x)						\

#define WARN_ON(x) ({						\

	typeof(x) __ret_warn_on = (x);				\

	if (__builtin_constant_p(__ret_warn_on)) {		\

		if (__ret_warn_on)				\

			__WARN();				\

	} else {						\

		__asm__ __volatile__(				\
@@ -80,11 +81,12 @@ struct bug_entry *find_bug(unsigned long bugaddr); 
		".section __bug_table,\"a\"\n"			\

		"\t"PPC_LONG"	1b,%1,%2,%3\n"			\

		".previous"					\

		: : "r" ((long)(x)),				\

		: : "r" (__ret_warn_on),			\

		    "i" (__LINE__ + BUG_WARNING_TRAP),		\

		    "i" (__FILE__), "i" (__FUNCTION__));	\

	}							\

} while (0)

	unlikely(__ret_warn_on);				\

})



#define HAVE_ARCH_BUG

#define HAVE_ARCH_BUG_ON

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