config/user-libatomic.m4

   1 dnl #
   2 dnl # If -latomic exists and atomic.c doesn't link without it,
   3 dnl # it's needed for __atomic intrinsics.
   4 dnl #
   5 AC_DEFUN([ZFS_AC_CONFIG_USER_LIBATOMIC], [
   6         AC_MSG_CHECKING([whether -latomic is required])
   7
   8         saved_libs="$LIBS"
   9         LIBS="$LIBS -latomic"
  10         LIBATOMIC_LIBS=""
  11
  12         AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])], [
  13                 LIBS="$saved_libs"
  14                 saved_cflags="$CFLAGS"
  15                 CFLAGS="$CFLAGS -isystem lib/libspl/include"
  16                 AC_LINK_IFELSE([AC_LANG_PROGRAM([#include "lib/libspl/atomic.c"], [])], [], [LIBATOMIC_LIBS="-latomic"])
  17                 CFLAGS="$saved_cflags"
  18         ])
  19
  20         if test -n "$LIBATOMIC_LIBS"; then
  21                 AC_MSG_RESULT([yes])
  22         else
  23                 AC_MSG_RESULT([no])
  24         fi
  25
  26         LIBS="$saved_libs"
  27         AC_SUBST([LIBATOMIC_LIBS])
  28 ])