SYNOPSIS
        mixed include_file (string file, string compiled_file, int sys_include)

DESCRIPTION
        Generate the pathname of an included file.

        Arguments:
          previous_object(): The object causing the compile.
          file             : The name given in the #include directive.
          compiled_file    : The object file which is just compiled.
                             (compat: name given without leading "/")
          sys_include      : TRUE for #include <> directives.

        Result:
          0: use the normal include filename generation (""-includes are
             used as they are, <>-includes are handled according to
             H_INCLUDE_DIRS).

          <path>: the full absolute pathname of the file to include,
                  without parentdir parts ("/../"). Leading slashes ("/")
                  may be omitted.

          else: The include directive is not legal.

        If the function does not generate a valid pathname, the driver
        will next try to resolve the include using the H_INCLUDE_DIRS hook.

HISTORY
        Introduced in LDMud 3.2.8.

SEE ALSO
        hooks(C), inherit_file(M), include_dirs(H)