X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/6b8bc570715801cb194dc4273370eab87628e8bf..5a44bfea9d4a6e6fbc8c74aa7e8691b47397927a:/lib/ignore-value.h

diff --git a/lib/ignore-value.h b/lib/ignore-value.h
index f021a1ac8e..6713d96f84 100644
--- a/lib/ignore-value.h
+++ b/lib/ignore-value.h
@@ -1,6 +1,6 @@
-/* ignore a function return without a compiler warning
+/* ignore a function return without a compiler warning.  -*- coding: utf-8 -*-
 
-   Copyright (C) 2008-2011 Free Software Foundation, Inc.
+   Copyright (C) 2008-2016 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -33,30 +33,18 @@
    declared with attribute warn_unused_result".  */
 
 #ifndef _GL_IGNORE_VALUE_H
-# define _GL_IGNORE_VALUE_H
-
-# ifndef _GL_ATTRIBUTE_DEPRECATED
-/* The __attribute__((__deprecated__)) feature
-   is available in gcc versions 3.1 and newer.  */
-#  if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 1)
-#   define _GL_ATTRIBUTE_DEPRECATED /* empty */
-#  else
-#   define _GL_ATTRIBUTE_DEPRECATED __attribute__ ((__deprecated__))
-#  endif
-# endif
-
-/* The __attribute__((__warn_unused_result__)) feature
-   is available in gcc versions 3.4 and newer,
-   while the typeof feature has been available since 2.7 at least.  */
-# if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 4)
-#  define ignore_value(x) ((void) (x))
-# else
-#  define ignore_value(x) (({ __typeof__ (x) __x = (x); (void) __x; }))
-# endif
-
-/* ignore_value works for scalars, pointers and aggregates;
-   deprecate ignore_ptr.  */
-static inline void _GL_ATTRIBUTE_DEPRECATED
-ignore_ptr (void *p) { (void) p; } /* deprecated: use ignore_value */
+#define _GL_IGNORE_VALUE_H
+
+/* Normally casting an expression to void discards its value, but GCC
+   versions 3.4 and newer have __attribute__ ((__warn_unused_result__))
+   which may cause unwanted diagnostics in that case.  Use __typeof__
+   and __extension__ to work around the problem, if the workaround is
+   known to be needed.  */
+#if 3 < __GNUC__ + (4 <= __GNUC_MINOR__)
+# define ignore_value(x) \
+    (__extension__ ({ __typeof__ (x) __x = (x); (void) __x; }))
+#else
+# define ignore_value(x) ((void) (x))
+#endif
 
 #endif