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      1 #
      2 # Check for anonymous mmap macros.  This is modified from
      3 # http://www.gnu.org/software/ac-archive/htmldoc/ac_cxx_have_ext_slist.html
      4 #
      5 AC_DEFUN([AC_HEADER_MMAP_ANONYMOUS],
      6 [AC_CACHE_CHECK(for MAP_ANONYMOUS vs. MAP_ANON,
      7 ac_cv_header_mmap_anon,
      8 [ AC_LANG_PUSH([C])
      9   AC_COMPILE_IFELSE([AC_LANG_PROGRAM(
     10     [[#include <sys/mman.h>
     11 #include <unistd.h>
     12 #include <fcntl.h>]],
     13   [[mmap (0, 1, PROT_READ, MAP_ANONYMOUS, -1, 0); return (0);]])],
     14   ac_cv_header_mmap_anon=yes, 
     15   ac_cv_header_mmap_anon=no)
     16   AC_LANG_POP([C])
     17 ])
     18 if test "$ac_cv_header_mmap_anon" = yes; then
     19    AC_DEFINE([HAVE_MMAP_ANONYMOUS],[1],[Define if mmap() uses MAP_ANONYMOUS to map anonymous pages, or undefine if it uses MAP_ANON])
     20 fi
     21 ])
     22