dnl Available from the GNU Autoconf Macro Archive at: dnl http://www.gnu.org/software/ac-archive/htmldoc/ac_compile_check_sizeof.html dnl AC_DEFUN([AC_COMPILE_CHECK_SIZEOF], [changequote(<<, >>)dnl dnl The name to #define. define(<>, translit(sizeof_$1, [a-z *], [A-Z_P]))dnl dnl The cache variable name. define(<>, translit(ac_cv_sizeof_$1, [ *], [_p]))dnl changequote([, ])dnl AC_MSG_CHECKING(size of $1) AC_CACHE_VAL(AC_CV_NAME, [for ac_size in 4 8 1 2 16 $2 ; do # List sizes in rough order of prevalence. AC_TRY_COMPILE([#include "confdefs.h" #include $2 ], [switch (0) case 0: case (sizeof ($1) == $ac_size):;], AC_CV_NAME=$ac_size) if test x$AC_CV_NAME != x ; then break; fi done ]) if test x$AC_CV_NAME = x ; then AC_MSG_ERROR([cannot determine a size for $1]) fi AC_MSG_RESULT($AC_CV_NAME) AC_DEFINE_UNQUOTED(AC_TYPE_NAME, $AC_CV_NAME, [The number of bytes in type $1]) undefine([AC_TYPE_NAME])dnl undefine([AC_CV_NAME])dnl ])