diff options
Diffstat (limited to 'autotools/m4/stddef_h.m4')
-rw-r--r-- | autotools/m4/stddef_h.m4 | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/autotools/m4/stddef_h.m4 b/autotools/m4/stddef_h.m4 index abfd2030..1bf9eb39 100644 --- a/autotools/m4/stddef_h.m4 +++ b/autotools/m4/stddef_h.m4 @@ -1,5 +1,5 @@ -# stddef_h.m4 serial 12 -dnl Copyright (C) 2009-2022 Free Software Foundation, Inc. +# stddef_h.m4 serial 14 +dnl Copyright (C) 2009-2024 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, dnl with or without modifications, as long as this notice is preserved. @@ -22,7 +22,14 @@ AC_DEFUN_ONCE([gl_STDDEF_H], [gl_cv_type_max_align_t], [AC_COMPILE_IFELSE( [AC_LANG_PROGRAM( - [[#include <stddef.h> + [[/* On FreeBSD 12.0/x86, max_align_t defined by <stddef.h> has + the correct alignment with the default (wrong) definition of + _Alignof, but a wrong alignment as soon as we activate an + ISO C compliant _Alignof definition. */ + #if ((defined __GNUC__ && 4 <= __GNUC__) || defined __clang__) && !defined __cplusplus + #define _Alignof(type) __builtin_offsetof (struct { char __a; type __b; }, __b) + #endif + #include <stddef.h> unsigned int s = sizeof (max_align_t); #if defined __GNUC__ || defined __clang__ || defined __IBM__ALIGNOF__ int check1[2 * (__alignof__ (double) <= __alignof__ (max_align_t)) - 1]; @@ -61,6 +68,21 @@ AC_DEFUN_ONCE([gl_STDDEF_H], GL_GENERATE_STDDEF_H=true fi + AC_CACHE_CHECK([for unreachable], + [gl_cv_func_unreachable], + [AC_LINK_IFELSE( + [AC_LANG_PROGRAM( + [[#include <stddef.h> + ]], + [[unreachable (); + ]])], + [gl_cv_func_unreachable=yes], + [gl_cv_func_unreachable=no]) + ]) + if test $gl_cv_func_unreachable = no; then + GL_GENERATE_STDDEF_H=true + fi + if $GL_GENERATE_STDDEF_H; then gl_NEXT_HEADERS([stddef.h]) fi |