cdefs.h: Retire __const and __signed

These are no longer used in the base system. Once upon a time they were
used to ease the transition from K&R to ANSI C. These days, we use both
of these keywords in their bare form everywhere, even in our
headers. Any uses of __const or __signed will be converted to their ANSI
meaning in the compiler, but is beyond the scope of cdefs.h's
charter. For pure K&R compilation, with an enforced only use K&R
features and meanings, one needs to define NO_ANSI_KEYWORDS (though even
that support is wobbly at best, being active only for !GCC or
gcc-adjacent compilers which currently appears to be none).

Sponsored by:		Netflix
Reviewed by:		brooks
Differential Revision:	https://reviews.freebsd.org/D45860

1 files changed, 0 insertions, 4 deletions

diff --git a/sys/sys/cdefs.h b/sys/sys/cdefs.h
index b92992c1b5c3..e08da15e1d91 100644
--- a/sys/sys/cdefs.h
+++ b/sys/sys/cdefs.h
@@ -124,8 +124,6 @@
 #define	__STRING(x)	#x		/* stringify without expanding x */
 #define	__XSTRING(x)	__STRING(x)	/* expand x, then stringify */
 
-#define	__const		const		/* define reserved names to standard */
-#define	__signed	signed
 #define	__volatile	volatile
 #if defined(__cplusplus)
 #define	__inline	inline		/* convert to C++ keyword */
@@ -141,9 +139,7 @@
 #define	__STRING(x)	"x"
 
 #if !defined(__CC_SUPPORTS___INLINE)
-#define	__const				/* delete pseudo-ANSI C keywords */
 #define	__inline
-#define	__signed
 #define	__volatile
 /*
  * In non-ANSI C environments, new programs will want ANSI-only C keywords