1 # mode_t.m4 serial 2 2 dnl Copyright (C) 2009-2012 Free Software Foundation, Inc. 3 dnl This file is free software; the Free Software Foundation 4 dnl gives unlimited permission to copy and/or distribute it, 5 dnl with or without modifications, as long as this notice is preserved. 6 7 # For using mode_t, it's sufficient to use AC_TYPE_MODE_T and 8 # include <sys/types.h>. 9 10 # Define PROMOTED_MODE_T to the type that is the result of "default argument 11 # promotion" (ISO C 6.5.2.2.(6)) of the type mode_t. 12 AC_DEFUN([gl_PROMOTED_TYPE_MODE_T], 13 [ 14 AC_REQUIRE([AC_TYPE_MODE_T]) 15 AC_CACHE_CHECK([for promoted mode_t type], [gl_cv_promoted_mode_t], [ 16 dnl Assume mode_t promotes to 'int' if and only if it is smaller than 'int', 17 dnl and to itself otherwise. This assumption is not guaranteed by the ISO C 18 dnl standard, but we don't know of any real-world counterexamples. 19 AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/types.h>]], 20 [[typedef int array[2 * (sizeof (mode_t) < sizeof (int)) - 1];]])], 21 [gl_cv_promoted_mode_t='int'], 22 [gl_cv_promoted_mode_t='mode_t']) 23 ]) 24 AC_DEFINE_UNQUOTED([PROMOTED_MODE_T], [$gl_cv_promoted_mode_t], 25 [Define to the type that is the result of default argument promotions of type mode_t.]) 26 ]) 27
