Re: [PATCH 5/7] signal: Silence nested-externs warnings

[Oleg Nesterov <oleg@redhat.com>]

On 09/19, Richard Weinberger wrote:
>
> Am 19.09.2014 17:37, schrieb Jeff Kirsher:
> >
> > See patch 1 of the series.
>
> I was not CC'ed...

Me too, and thus I don't understand this patch.

But I have to admit it looks a bit ugly to me anyway.
Can't we simply kill _NSIG_WORDS_is_unsupported_size ?

Oleg.
---

diff --git a/include/linux/signal.h b/include/linux/signal.h
index 750196f..679c9b4 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -67,7 +67,6 @@ static inline int sigismember(sigset_t *set, int _sig)
 
 static inline int sigisemptyset(sigset_t *set)
 {
-	extern void _NSIG_WORDS_is_unsupported_size(void);
 	switch (_NSIG_WORDS) {
 	case 4:
 		return (set->sig[3] | set->sig[2] |
@@ -77,7 +76,7 @@ static inline int sigisemptyset(sigset_t *set)
 	case 1:
 		return set->sig[0] == 0;
 	default:
-		_NSIG_WORDS_is_unsupported_size();
+		BUILD_BUG();
 		return 0;
 	}
 }
@@ -90,7 +89,6 @@ static inline int sigisemptyset(sigset_t *set)
 #define _SIG_SET_BINOP(name, op)					\
 static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
 {									\
-	extern void _NSIG_WORDS_is_unsupported_size(void);		\
 	unsigned long a0, a1, a2, a3, b0, b1, b2, b3;			\
 									\
 	switch (_NSIG_WORDS) {						\
@@ -107,7 +105,7 @@ static inline void name(sigset_t *r, const sigset_t *a, const sigset_t *b) \
 		r->sig[0] = op(a0, b0);					\
 		break;							\
 	    default:							\
-		_NSIG_WORDS_is_unsupported_size();			\
+	    	BUILD_BUG();						\
 	}								\
 }
 
@@ -128,8 +126,6 @@ _SIG_SET_BINOP(sigandnsets, _sig_andn)
 #define _SIG_SET_OP(name, op)						\
 static inline void name(sigset_t *set)					\
 {									\
-	extern void _NSIG_WORDS_is_unsupported_size(void);		\
-									\
 	switch (_NSIG_WORDS) {						\
 	    case 4: set->sig[3] = op(set->sig[3]);			\
 		    set->sig[2] = op(set->sig[2]);			\
@@ -137,7 +133,7 @@ static inline void name(sigset_t *set)					\
 	    case 1: set->sig[0] = op(set->sig[0]);			\
 		    break;						\
 	    default:							\
-		_NSIG_WORDS_is_unsupported_size();			\
+		BUILD_BUG();						\
 	}								\
 }