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| author | Bruno Haible <bruno@clisp.org> | 2018-09-06 22:44:01 +0200 |
|---|---|---|
| committer | Bruno Haible <bruno@clisp.org> | 2018-09-06 22:44:01 +0200 |
| commit | 2788ef64e87c4cdb786ff08d2cd00ecae76676ee (patch) | |
| tree | fcc0d5e704becb292ebdaced90a3aa9a9d505ba0 /m4/stddef_h.m4 | |
| parent | c4af52baedd099698d83e204f67510678230cd16 (diff) | |
| download | gnulib-2788ef64e87c4cdb786ff08d2cd00ecae76676ee.tar.gz | |
stddef: Override max_align_t on NetBSD 8.0/x86.
* m4/stddef_h.m4 (gl_STDDEF_H): When testing for max_align_t, test also
the value of __alignof__ (max_align_t).
* doc/posix-headers/stddef.texi: Mention the issue.
Diffstat (limited to 'm4/stddef_h.m4')
| -rw-r--r-- | m4/stddef_h.m4 | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/m4/stddef_h.m4 b/m4/stddef_h.m4 index ba3d201cf3..07b040abdf 100644 --- a/m4/stddef_h.m4 +++ b/m4/stddef_h.m4 @@ -1,5 +1,5 @@ dnl A placeholder for <stddef.h>, for platforms that have issues. -# stddef_h.m4 serial 5 +# stddef_h.m4 serial 6 dnl Copyright (C) 2009-2018 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -10,13 +10,33 @@ 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> - ]]) + + dnl Test whether the type max_align_t exists and whether its alignment + dnl "is as great as is supported by the implementation in all contexts". + AC_CACHE_CHECK([for good max_align_t], + [gl_cv_type_max_align_t], + [AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM( + [[#include <stddef.h> + unsigned int s = sizeof (max_align_t); + #if defined __GNUC__ || defined __IBM__ALIGNOF__ + int check1[2 * (__alignof__ (double) <= __alignof__ (max_align_t)) - 1]; + int check2[2 * (__alignof__ (long double) <= __alignof__ (max_align_t)) - 1]; + #endif + ]])], + [gl_cv_type_max_align_t=yes], + [gl_cv_type_max_align_t=no]) + ]) + if test $gl_cv_type_max_align_t = no; then + HAVE_MAX_ALIGN_T=0 + STDDEF_H=stddef.h + fi + if test $gt_cv_c_wchar_t = no; then HAVE_WCHAR_T=0 STDDEF_H=stddef.h fi + AC_CACHE_CHECK([whether NULL can be used in arbitrary expressions], [gl_cv_decl_null_works], [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <stddef.h> @@ -28,6 +48,7 @@ AC_DEFUN([gl_STDDEF_H], REPLACE_NULL=1 STDDEF_H=stddef.h fi + AC_SUBST([STDDEF_H]) AM_CONDITIONAL([GL_GENERATE_STDDEF_H], [test -n "$STDDEF_H"]) if test -n "$STDDEF_H"; then |