svn commit: r307756 - in head: include sys/sys
John Baldwin
jhb at FreeBSD.org
Fri Oct 21 23:50:04 UTC 2016
Author: jhb
Date: Fri Oct 21 23:50:02 2016
New Revision: 307756
URL: https://svnweb.freebsd.org/changeset/base/307756
Log:
Define max_align_t for C11.
libc++'s stddef.h includes an existing definition of max_align_t for
C++11, but it is only defined for C++, not for C. In addition, GCC and
clang both define an alternate version of max_align_t that uses a
union of multiple types rather than a plain long double as in libc++.
This adds a __max_align_t to <sys/_types.h> that matches the GCC and
clang definition that is mapped to max_align_t in <stddef.h>.
PR: 210890
Reviewed by: dim
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D8194
Modified:
head/include/stddef.h
head/sys/sys/_types.h
Modified: head/include/stddef.h
==============================================================================
--- head/include/stddef.h Fri Oct 21 21:55:50 2016 (r307755)
+++ head/include/stddef.h Fri Oct 21 23:50:02 2016 (r307756)
@@ -62,6 +62,14 @@ typedef ___wchar_t wchar_t;
#endif
#endif
+#if __STDC_VERSION__ >= 201112L || __cplusplus >= 201103L
+#ifndef __CLANG_MAX_ALIGN_T_DEFINED
+typedef __max_align_t max_align_t;
+#define __CLANG_MAX_ALIGN_T_DEFINED
+#define __GCC_MAX_ALIGN_T
+#endif
+#endif
+
#define offsetof(type, member) __offsetof(type, member)
#endif /* _STDDEF_H_ */
Modified: head/sys/sys/_types.h
==============================================================================
--- head/sys/sys/_types.h Fri Oct 21 21:55:50 2016 (r307755)
+++ head/sys/sys/_types.h Fri Oct 21 23:50:02 2016 (r307756)
@@ -100,6 +100,11 @@ typedef __uint_least32_t __char32_t;
#define _CHAR32_T_DECLARED
#endif
+typedef struct {
+ long long __max_align1 __aligned(_Alignof(long long));
+ long double __max_align2 __aligned(_Alignof(long double));
+} __max_align_t;
+
typedef __uint32_t __dev_t; /* device number */
typedef __uint32_t __fixpt_t; /* fixed point number */
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