| # ffs.m4 serial 4 |
| dnl Copyright (C) 2011-2021 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_FUNC_FFS], |
| [ |
| AC_REQUIRE([gl_HEADER_STRINGS_H_DEFAULTS]) |
| |
| dnl We can't use AC_CHECK_FUNC here, because ffs() is defined as a |
| dnl static inline function when compiling for Android 4.2 or older. |
| dnl But require that ffs() is declared; otherwise we may be using |
| dnl the GCC built-in function, which leads to warnings |
| dnl "warning: implicit declaration of function 'ffs'". |
| AC_CACHE_CHECK([for ffs], [gl_cv_func_ffs], |
| [AC_LINK_IFELSE( |
| [AC_LANG_PROGRAM( |
| [[#include <strings.h> |
| int x; |
| ]], |
| [[int (*func) (int) = ffs; |
| return func (x); |
| ]]) |
| ], |
| [gl_cv_func_ffs=yes], |
| [gl_cv_func_ffs=no]) |
| ]) |
| if test $gl_cv_func_ffs = no; then |
| HAVE_FFS=0 |
| fi |
| ]) |
