| 1 | # mode_t.m4 serial 2 |
| 2 | dnl Copyright (C) 2009-2013 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 | ]) |