git.m6w6.name Git - m6w6/libmemcached/blob - m4/bitfield.m4

   1 AC_DEFUN([DETECT_BITFIELD],
   2 [
   3     AC_CACHE_CHECK([for working bitfield],[ac_cv_have_bitfield],[
   4     AC_LANG_PUSH([C])
   5     save_CFLAGS="${CFLAGS}"
   6     CFLAGS="${AM_CFLAGS} ${NO_WERROR}"
   7
   8     AC_RUN_IFELSE([
   9        AC_LANG_PROGRAM([[
  10 #include <stdbool.h>
  11        ]],[[
  12    struct flags { bool b0:1; bool b1:1; bool b2:1; bool b3:1;
  13                   bool b4:1; bool b5:1; bool b6:1; bool b7:1;
  14    } f = { .b0 = false, .b1 = false, .b2 = false, .b3 = false,
  15            .b4 = false, .b5 = false, .b6 = false, .b7 = false };
  16
  17    f.b0 = true;
  18    f.b1 = false;
  19    f.b2 = true;
  20    f.b3 = false;
  21    f.b4 = true;
  22    f.b5 = false;
  23    f.b6 = true;
  24    f.b7 = false;
  25
  26    if (f.b0 && !f.b1 && f.b2 && !f.b3 && f.b4 && !f.b5 && f.b6 && !f.b7) {
  27       return 0;
  28    }
  29
  30    return 1;
  31        ]])
  32     ], [
  33       ac_cv_have_bitfield=yes
  34     ],[
  35       ac_cv_have_bitfield=no
  36     ])])
  37
  38     CFLAGS=${save_CFLAGS}
  39     AS_IF([test "x$ac_cv_have_bitfield" = "xyes"],
  40           [
  41             MEMCACHED_BITFIELD="#define MEMCACHED_BITFIELD :1"
  42             HASHKIT_BITFIELD="#define HASHKIT_BITFIELD :1"
  43           ],
  44           [
  45             MEMCACHED_BITFIELD="#define MEMCACHED_BITFIELD"
  46             HASHKIT_BITFIELD="#define HASHKIT_BITFIELD"
  47           ])
  48     AC_SUBST([MEMCACHED_BITFIELD])
  49     AC_SUBST([HASHKIT_BITFIELD])
  50     AC_LANG_POP()
  51 ])