From a7ae78caaa17ff840da844c1dcaa780d194c9e20 Mon Sep 17 00:00:00 2001 From: Andrew Turner Date: Wed, 12 Jun 2024 14:04:13 +0100 Subject: [PATCH] cdefs: Add __writeonly to mark write only vars When a variable in write only and can't be removed, e.g. for API reasons, it is useful to document this fact similar to __diagused and __witness_used. Add __writeonly to tell the compiler and anyone looking at the code that this variable is expected to only be written to, and to not raise and error. Reviewed by: imp, kib Sponsored by: Arm Ltd Differential Revision: https://reviews.freebsd.org/D45561 --- sys/sys/cdefs.h | 1 + 1 file changed, 1 insertion(+) diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h index 037dfa55f923..c3268791787f 100644 --- a/sys/sys/cdefs.h +++ b/sys/sys/cdefs.h @@ -180,6 +180,7 @@ #define __aligned(x) __attribute__((__aligned__(x))) #define __section(x) __attribute__((__section__(x))) #endif +#define __writeonly __unused #if __GNUC_PREREQ__(4, 3) || __has_attribute(__alloc_size__) #define __alloc_size(x) __attribute__((__alloc_size__(x))) #define __alloc_size2(n, x) __attribute__((__alloc_size__(n, x)))