git: f0d034474236 - stable/12 - Add __diagused

[Mateusz Guzik]

The branch stable/12 has been updated by mjg:

URL: https://cgit.FreeBSD.org/src/commit/?id=f0d0344742365c8fd548a2be6a31f0a9fe9b54a8

commit f0d0344742365c8fd548a2be6a31f0a9fe9b54a8
Author:     Mateusz Guzik <mjg at FreeBSD.org>
AuthorDate: 2021-07-15 14:01:02 +0000
Commit:     Mateusz Guzik <mjg at FreeBSD.org>
CommitDate: 2021-07-25 07:05:24 +0000

    Add __diagused
    
    This can be used for variables which are only used with either
    INVARIANTS or WITNESS. Without any annotation they run into dead store
    warnings from cc --analyze and always annotating with __unused may hide
    bad vars when it should not.
    
    Reviewed by:    kib, markj
    Sponsored by:   Rubicon Communications, LLC ("Netgate")
    Differential Revision:  https://reviews.freebsd.org/D31185
    
    (cherry picked from commit b9296725cf99696b48926270a553044522d6e344)
---
 sys/sys/systm.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index 37dd13654971..0c1d392fd740 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -583,6 +583,15 @@ void _gone_in_dev(struct device *dev, int major, const char *msg);
 	gone_in_dev((dev), 13,						\
 	    "see https://github.com/freebsd/fcp/blob/master/fcp-0101.md")
 
+#ifdef _KERNEL
+#if defined(INVARIANTS) || defined(WITNESS)
+#define	__diagused
+#else
+#define	__diagused	__unused
+#endif
+
+#endif /* _KERNEL */
+
 __NULLABILITY_PRAGMA_POP
 
 #endif /* !_SYS_SYSTM_H_ */