diff options
Diffstat (limited to 'gnulib-m4/stddef_h.m4')
| -rw-r--r-- | gnulib-m4/stddef_h.m4 | 76 |
1 files changed, 61 insertions, 15 deletions
diff --git a/gnulib-m4/stddef_h.m4 b/gnulib-m4/stddef_h.m4 index ba3d201c..abfd2030 100644 --- a/gnulib-m4/stddef_h.m4 +++ b/gnulib-m4/stddef_h.m4 @@ -1,22 +1,54 @@ -dnl A placeholder for <stddef.h>, for platforms that have issues. -# stddef_h.m4 serial 5 -dnl Copyright (C) 2009-2018 Free Software Foundation, Inc. +# stddef_h.m4 serial 12 +dnl Copyright (C) 2009-2022 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. -AC_DEFUN([gl_STDDEF_H], +dnl A placeholder for <stddef.h>, for platforms that have issues. + +AC_DEFUN_ONCE([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 Persuade OpenBSD <stddef.h> to declare max_align_t. + AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) + + GL_GENERATE_STDDEF_H=false + + 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 __clang__ || 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 + typedef struct { char a; max_align_t b; } max_helper; + typedef struct { char a; long b; } long_helper; + typedef struct { char a; double b; } double_helper; + typedef struct { char a; long double b; } long_double_helper; + int check3[2 * (offsetof (long_helper, b) <= offsetof (max_helper, b)) - 1]; + int check4[2 * (offsetof (double_helper, b) <= offsetof (max_helper, b)) - 1]; + int check5[2 * (offsetof (long_double_helper, b) <= offsetof (max_helper, b)) - 1]; + ]])], + [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 + GL_GENERATE_STDDEF_H=true + fi + if test $gt_cv_c_wchar_t = no; then HAVE_WCHAR_T=0 - STDDEF_H=stddef.h + GL_GENERATE_STDDEF_H=true 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> @@ -26,22 +58,36 @@ AC_DEFUN([gl_STDDEF_H], [gl_cv_decl_null_works=no])]) if test $gl_cv_decl_null_works = no; then REPLACE_NULL=1 - STDDEF_H=stddef.h + GL_GENERATE_STDDEF_H=true fi - AC_SUBST([STDDEF_H]) - AM_CONDITIONAL([GL_GENERATE_STDDEF_H], [test -n "$STDDEF_H"]) - if test -n "$STDDEF_H"; then + + if $GL_GENERATE_STDDEF_H; then gl_NEXT_HEADERS([stddef.h]) fi ]) +# gl_STDDEF_MODULE_INDICATOR([modulename]) +# sets the shell variable that indicates the presence of the given module +# to a C preprocessor expression that will evaluate to 1. +# This macro invocation must not occur in macros that are AC_REQUIREd. AC_DEFUN([gl_STDDEF_MODULE_INDICATOR], [ - dnl Use AC_REQUIRE here, so that the default settings are expanded once only. - AC_REQUIRE([gl_STDDEF_H_DEFAULTS]) + dnl Ensure to expand the default settings once only. + gl_STDDEF_H_REQUIRE_DEFAULTS gl_MODULE_INDICATOR_SET_VARIABLE([$1]) ]) +# Initializes the default values for AC_SUBSTed shell variables. +# This macro must not be AC_REQUIREd. It must only be invoked, and only +# outside of macros or in macros that are not AC_REQUIREd. +AC_DEFUN([gl_STDDEF_H_REQUIRE_DEFAULTS], +[ + m4_defun(GL_MODULE_INDICATOR_PREFIX[_STDDEF_H_MODULE_INDICATOR_DEFAULTS], [ + ]) + m4_require(GL_MODULE_INDICATOR_PREFIX[_STDDEF_H_MODULE_INDICATOR_DEFAULTS]) + AC_REQUIRE([gl_STDDEF_H_DEFAULTS]) +]) + AC_DEFUN([gl_STDDEF_H_DEFAULTS], [ dnl Assume proper GNU behavior unless another module says otherwise. |