| # ffs.m4 | |
| # serial 6 | |
| dnl Copyright (C) 2011-2026 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. | |
| dnl This file is offered as-is, without any warranty. | |
| AC_DEFUN([gl_FUNC_FFS], | |
| [ | |
| AC_REQUIRE([gl_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 13 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 | |
| ]) |