m4/ax_c_lto.m4

   1 # AC_C_LTO
   2 # -------------
   3 # Define HAVE_LTO if -flto works.
   4 AN_IDENTIFIER([lto], [AC_C_LTO])
   5 AC_DEFUN([AC_C_LTO],
   6 [AC_CACHE_CHECK([if -flto builds executables], ac_cv_c_lto,
   7 [AC_RUN_IFELSE(
   8    [AC_LANG_SOURCE(
   9       [[#include <stdio.h>
  10         int main(int argc, char **argv) {
  11           return 0;
  12         }
  13       ]])],
  14    [ac_cv_c_lto=yes],
  15    [ac_cv_c_lto=no],
  16    [ac_cv_c_lto=${ac_cv_c_lto_cross_compile}])])
  17 if test "${ac_cv_c_lto}" = "yes"; then
  18   AC_DEFINE([HAVE_LTO], 1,
  19            [Define to 1 if -flto works.])
  20 fi
  21 ])# AC_C_LTO