Lame AC_FUNC_MMAP

[Bob Friesenhahn]

Our application has been using AC_FUNC_MMAP to test for a working
mmap().  This macro is now described as:

AC_FUNC_MMAP
    If the mmap function exists and works correctly, define HAVE_MMAP.
    Only checks private fixed mapping of already-mapped memory.

Notice that it is only checking private fixed mapping.  This is just
one use of mmap, and not even a recommended one.

It seems to me that there should be one macro to test this ability to
handle private fixed mapping (e.g. "AC_FUNC_MMAP_PRIVATE"), and
another macro to test the ability to properly access and update a file
via mmap() ("AC_FUNC_MMAP_FILE").

Bob
======================================
Bob Friesenhahn
address@hidden
http://www.simplesystems.org/users/bfriesen