[src/trunk]: src/sys/sys Add a new macro, __GNUC_PREREQ__(major, minor) which...

[thorpej <thorpej%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/b4a7152aa784
branches:  trunk
changeset: 485765:b4a7152aa784
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Fri May 05 00:19:04 2000 +0000

description:
Add a new macro, __GNUC_PREREQ__(major, minor) which tests to see if
the compiler is GCC and at least the version specified by <major,minor>,
and use it in a few appropriate places in this file.

diffstat:

 sys/sys/cdefs.h |  26 ++++++++++++++++++++++----
 1 files changed, 22 insertions(+), 4 deletions(-)

diffs (54 lines):

diff -r 4d437d20ab73 -r b4a7152aa784 sys/sys/cdefs.h
--- a/sys/sys/cdefs.h   Thu May 04 21:56:47 2000 +0000
+++ b/sys/sys/cdefs.h   Fri May 05 00:19:04 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cdefs.h,v 1.31 2000/02/03 02:20:13 cgd Exp $   */
+/*     $NetBSD: cdefs.h,v 1.32 2000/05/05 00:19:04 thorpej Exp $       */
 
 /*
  * Copyright (c) 1991, 1993
@@ -41,6 +41,25 @@
 #ifndef        _SYS_CDEFS_H_
 #define        _SYS_CDEFS_H_
 
+/*
+ * Macro to test if we're using a GNU C compiler of a specific vintage
+ * or later, for e.g. features that appeared in a particular version
+ * of GNU C.  Usage:
+ *
+ *     #if __GNUC_PREREQ__(major, minor)
+ *     ...cool feature...
+ *     #else
+ *     ...delete feature...
+ *     #endif
+ */
+#ifdef __GNUC__
+#define        __GNUC_PREREQ__(x, y)                                           \
+       ((__GNUC__ == (x) && __GNUC_MINOR__ >= (y)) ||                  \
+        (__GNUC__ > (x)))
+#else
+#define        __GNUC_PREREQ__(x, y)   0
+#endif
+
 #include <machine/cdefs.h>
 #ifdef __ELF__
 #include <sys/cdefs_elf.h>
@@ -122,7 +141,7 @@
  * GCC2 provides __extension__ to suppress warnings for various GNU C
  * language extensions under "-ansi -pedantic".
  */
-#if !defined(__GNUC__) || __GNUC__ < 2
+#if !__GNUC_PREREQ__(2, 0)
 #define        __extension__           /* delete __extension__ if non-gcc or gcc1 */
 #endif
 
@@ -134,8 +153,7 @@
  * these work for GNU C++ (modulo a slight glitch in the C++ grammar
  * in the distribution version of 2.5.5).
  */
-#if !defined(__GNUC__) || __GNUC__ < 2 || \
-       (__GNUC__ == 2 && __GNUC_MINOR__ < 5)
+#if !__GNUC_PREREQ__(2, 5)
 #define        __attribute__(x)        /* delete __attribute__ if non-gcc or gcc1 */
 #if defined(__GNUC__) && !defined(__STRICT_ANSI__)
 #define        __dead          __volatile