cdefs: Add __deprecated(message) function attribute macro

The legacy version of GCC4 currently in base does not support the
parameterized form of this function attribute, as recent introduced in
stdlib.h (r355747).

As we have done for other function attributes with similar compatibility
problems, add a version-compatibile definition in sys/cdefs.h.  Note that
Clang defines itself to be GCC 4, so one must check for __clang__ in
addition to __GNUC__ version.  On legacy GCC 4, the macro expands to just
the __deprecated__ attribute; on modern GCC or Clang, the macro expands to
the parameterized variant with the message.

Ignoring legacy or unsupported compilers, the macro is also beneficial in
that it is a bit more ergonomic than the full
__attribute__((__deprecated__())) boilerplate.

Reported by:	CI (but not tinderbox); imp and others
Reviewed by:	imp
Differential Revision:	https://reviews.freebsd.org/D22817
This commit is contained in:
Conrad Meyer 2019-12-14 21:52:49 +00:00
parent 547a4dba9f
commit 215332ffe7
2 changed files with 9 additions and 1 deletions

View File

@ -315,7 +315,7 @@ long long
/* Deprecated interfaces, to be removed. */
static inline void
__attribute__((__deprecated__("sranddev to be removed in FreeBSD 13")))
__deprecated("sranddev to be removed in FreeBSD 13")
sranddev(void)
{
}

View File

@ -468,6 +468,14 @@
#define __hidden
#endif
#if __GNUC__ > 4 || defined(__clang__)
#define __deprecated(m) __attribute__((__deprecated__(m)))
#elif defined(__GNUC__)
#define __deprecated(m) __attribute__((__deprecated__))
#else
#define __deprecated(m)
#endif
/*
* We define this here since <stddef.h>, <sys/queue.h>, and <sys/types.h>
* require it.