svn commit: r321376 - head/sys/compat/linuxkpi/common/include/linux

[Ryan Libby]

Author: rlibby
Date: Sat Jul 22 21:29:44 2017
New Revision: 321376
URL: https://svnweb.freebsd.org/changeset/base/321376

Log:
  linuxkpi compiler.h: avoid gcc -Wunused-value in dummy expressions
  
  It looks like the __acquire and __release macros are for the consumption
  of static analysis tools and have no semantic effect.  Transform the
  definitions from constant expressions to empty statements in order to
  avoid -Wunused-value from gcc.
  
  Likewise avoid future warnings for __chk_{user,io}_ptr, but with a cast
  to void, because it looks like some linux kernel code may use those in
  expression contexts.
  
  Reviewed by:	hselasky, markj
  Approved by:	markj (mentor)
  Sponsored by:	Dell EMC Isilon
  Differential Revision: https://reviews.freebsd.org/D11695

Modified:
  head/sys/compat/linuxkpi/common/include/linux/compiler.h

Modified: head/sys/compat/linuxkpi/common/include/linux/compiler.h
==============================================================================
--- head/sys/compat/linuxkpi/common/include/linux/compiler.h	Sat Jul 22 17:49:18 2017	(r321375)
+++ head/sys/compat/linuxkpi/common/include/linux/compiler.h	Sat Jul 22 21:29:44 2017	(r321376)
@@ -40,13 +40,13 @@
 #define __force
 #define __nocast
 #define __iomem
-#define __chk_user_ptr(x)		0
-#define __chk_io_ptr(x)			0
+#define __chk_user_ptr(x)		((void)0)
+#define __chk_io_ptr(x)			((void)0)
 #define __builtin_warning(x, y...)	(1)
 #define __acquires(x)
 #define __releases(x)
-#define __acquire(x)			0
-#define __release(x)			0
+#define __acquire(x)			do { } while (0)
+#define __release(x)			do { } while (0)
 #define __cond_lock(x,c)		(c)
 #define	__bitwise
 #define __devinitdata