* doc/posix-headers/stddef.texi (stddef.h): Document max_align_t.
* lib/stddef.in.h (_@GUARD_PREFIX@_STDDEF_H) [__need_wint_t]:
Do not undef, as that might cause max_align_t to be defined twice.
Instead, change use to check for _GL_STDDEF_WINT_T too.
(max_align_t) [!HAVE_MAX_ALIGN_T]: New decl.
* m4/stddef_h.m4 (gl_STDDEF_H, gl_STDDEF_H_DEFAULTS):
Check for max_align_t.
* modules/stddef (stddef.h): Substitute HAVE_MAX_ALIGN_T.
* modules/stddef-tests (Depends-on): Add stdalign.
* tests/test-stddef.c: Test max_align_t.
---
ChangeLog | 14 ++++++++++++++
doc/posix-headers/stddef.texi | 3 +++
lib/stddef.in.h | 41 ++++++++++++++++++++++++++---------------
m4/stddef_h.m4 | 8 ++++++--
modules/stddef | 1 +
modules/stddef-tests | 1 +
tests/test-stddef.c | 13 ++++++++++++-
7 files changed, 63 insertions(+), 18 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 2336ee5..df4d8d4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2014-12-12 Paul Eggert <egg...@cs.ucla.edu>
+
+ stddef: support C11's max_align_t
+ * doc/posix-headers/stddef.texi (stddef.h): Document max_align_t.
+ * lib/stddef.in.h (_@GUARD_PREFIX@_STDDEF_H) [__need_wint_t]:
+ Do not undef, as that might cause max_align_t to be defined twice.
+ Instead, change use to check for _GL_STDDEF_WINT_T too.
+ (max_align_t) [!HAVE_MAX_ALIGN_T]: New decl.
+ * m4/stddef_h.m4 (gl_STDDEF_H, gl_STDDEF_H_DEFAULTS):
+ Check for max_align_t.
+ * modules/stddef (stddef.h): Substitute HAVE_MAX_ALIGN_T.
+ * modules/stddef-tests (Depends-on): Add stdalign.
+ * tests/test-stddef.c: Test max_align_t.
+
2014-12-11 Daiki Ueno <u...@gnu.org>
unistd: fix iOS check conditional
diff --git a/doc/posix-headers/stddef.texi b/doc/posix-headers/stddef.texi
index 6174b1f..77b3d3b 100644
--- a/doc/posix-headers/stddef.texi
+++ b/doc/posix-headers/stddef.texi
@@ -8,6 +8,9 @@ Gnulib module: stddef
Portability problems fixed by Gnulib:
@itemize
@item
+Some platforms fail to provide @code{max_align_t}, which was added in C11.
+
+@item
Some old platforms fail to provide @code{wchar_t}.
@item
diff --git a/lib/stddef.in.h b/lib/stddef.in.h
index 11b58be..6032526 100644
--- a/lib/stddef.in.h
+++ b/lib/stddef.in.h
@@ -39,7 +39,6 @@
# if !(defined _@GUARD_PREFIX@_STDDEF_H && defined _GL_STDDEF_WINT_T)
# ifdef __need_wint_t
-# undef _@GUARD_PREFIX@_STDDEF_H
# define _GL_STDDEF_WINT_T
# endif
# @INCLUDE_NEXT@ @NEXT_STDDEF_H@
@@ -54,33 +53,45 @@
# @INCLUDE_NEXT@ @NEXT_STDDEF_H@
-# ifndef _@GUARD_PREFIX@_STDDEF_H
-# define _@GUARD_PREFIX@_STDDEF_H
-
/* On NetBSD 5.0, the definition of NULL lacks proper parentheses. */
-#if @REPLACE_NULL@
-# undef NULL
-# ifdef __cplusplus
+# if (@REPLACE_NULL@ \
+ && (!defined _@GUARD_PREFIX@_STDDEF_H || defined _GL_STDDEF_WINT_T))
+# undef NULL
+# ifdef __cplusplus
/* ISO C++ says that the macro NULL must expand to an integer constant
expression, hence '((void *) 0)' is not allowed in C++. */
-# if __GNUG__ >= 3
+# if __GNUG__ >= 3
/* GNU C++ has a __null macro that behaves like an integer ('int' or
'long') but has the same size as a pointer. Use that, to avoid
warnings. */
-# define NULL __null
-# else
-# define NULL 0L
+# define NULL __null
+# else
+# define NULL 0L
+# endif
+# else
+# define NULL ((void *) 0)
+# endif
# endif
-# else
-# define NULL ((void *) 0)
-# endif
-#endif
+
+# ifndef _@GUARD_PREFIX@_STDDEF_H
+# define _@GUARD_PREFIX@_STDDEF_H
/* Some platforms lack wchar_t. */
#if !@HAVE_WCHAR_T@
# define wchar_t int
#endif
+/* Some platforms lack max_align_t. */
+#if !@HAVE_MAX_ALIGN_T@
+typedef union
+{
+ char *__p;
+ double __d;
+ long double __ld;
+ long int __i;
+} max_align_t;
+#endif
+
# endif /* _@GUARD_PREFIX@_STDDEF_H */
# endif /* _@GUARD_PREFIX@_STDDEF_H */
#endif /* __need_XXX */
diff --git a/m4/stddef_h.m4 b/m4/stddef_h.m4
index c555e29..9659813 100644
--- a/m4/stddef_h.m4
+++ b/m4/stddef_h.m4
@@ -1,5 +1,5 @@
-dnl A placeholder for POSIX 2008 <stddef.h>, for platforms that have issues.
-# stddef_h.m4 serial 4
+dnl A placeholder for <stddef.h>, for platforms that have issues.
+# stddef_h.m4 serial 5
dnl Copyright (C) 2009-2014 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
@@ -10,6 +10,9 @@ AC_DEFUN([gl_STDDEF_H],
AC_REQUIRE([gl_STDDEF_H_DEFAULTS])
AC_REQUIRE([gt_TYPE_WCHAR_T])
STDDEF_H=
+ AC_CHECK_TYPE([max_align_t], [], [HAVE_MAX_ALIGN_T=0; STDDEF_H=stddef.h],
+ [[#include <stddef.h>
+ ]])
if test $gt_cv_c_wchar_t = no; then
HAVE_WCHAR_T=0
STDDEF_H=stddef.h
@@ -43,5 +46,6 @@ AC_DEFUN([gl_STDDEF_H_DEFAULTS],
[
dnl Assume proper GNU behavior unless another module says otherwise.
REPLACE_NULL=0; AC_SUBST([REPLACE_NULL])
+ HAVE_MAX_ALIGN_T=1; AC_SUBST([HAVE_MAX_ALIGN_T])
HAVE_WCHAR_T=1; AC_SUBST([HAVE_WCHAR_T])
])
diff --git a/modules/stddef b/modules/stddef
index fd4cf50..99794a9 100644
--- a/modules/stddef
+++ b/modules/stddef
@@ -26,6 +26,7 @@ stddef.h: stddef.in.h $(top_builddir)/config.status
-e 's|@''PRAGMA_SYSTEM_HEADER''@|@PRAGMA_SYSTEM_HEADER@|g' \
-e 's|@''PRAGMA_COLUMNS''@|@PRAGMA_COLUMNS@|g' \
-e 's|@''NEXT_STDDEF_H''@|$(NEXT_STDDEF_H)|g' \
+ -e 's|@''HAVE_MAX_ALIGN_T''@|$(HAVE_MAX_ALIGN_T)|g' \
-e 's|@''HAVE_WCHAR_T''@|$(HAVE_WCHAR_T)|g' \
-e 's|@''REPLACE_NULL''@|$(REPLACE_NULL)|g' \
< $(srcdir)/stddef.in.h; \
diff --git a/modules/stddef-tests b/modules/stddef-tests
index 622ece5..cef92fa 100644
--- a/modules/stddef-tests
+++ b/modules/stddef-tests
@@ -2,6 +2,7 @@ Files:
tests/test-stddef.c
Depends-on:
+stdalign
verify
configure.ac:
diff --git a/tests/test-stddef.c b/tests/test-stddef.c
index d5d887e..0b8649d 100644
--- a/tests/test-stddef.c
+++ b/tests/test-stddef.c
@@ -19,13 +19,14 @@
#include <config.h>
#include <stddef.h>
-
+#include <stdalign.h>
#include "verify.h"
/* Check that appropriate types are defined. */
wchar_t a = 'c';
ptrdiff_t b = 1;
size_t c = 2;
+max_align_t x;
/* Check that NULL can be passed through varargs as a pointer type,
per POSIX 2008. */
@@ -45,6 +46,16 @@ verify (sizeof (offsetof (struct d, e)) == sizeof (size_t));
verify (offsetof (struct d, e) < -1); /* Must be unsigned. */
verify (offsetof (struct d, f) == 1);
+/* Check max_align_t's alignment. */
+verify (alignof (double) <= alignof (max_align_t));
+verify (alignof (int) <= alignof (max_align_t));
+verify (alignof (long double) <= alignof (max_align_t));
+verify (alignof (long int) <= alignof (max_align_t));
+verify (alignof (ptrdiff_t) <= alignof (max_align_t));
+verify (alignof (size_t) <= alignof (max_align_t));
+verify (alignof (wchar_t) <= alignof (max_align_t));
+verify (alignof (struct d) <= alignof (max_align_t));
+
int
main (void)
{
--
1.9.3
