Summary

Deprecate -Xfuture option from java launcher.

Problem

The -Xfuture was added as a way to encapsulate feature which were going to become default in some future version. Hotspot haven't been using it for that for at least a decade, and the only effect it has effectively had is passing -Xverify:all to the VM.

Solution

Deprecate the -Xfuture option in man page and help messages. Also print out an error message when the option is used.

Specification

For java -X,

-Xfuture          enable strictest checks, anticipating future default
                  This option is deprecated and may be removed in a
                  future release.

For man java,

   -Xfuture
       Enables strict class-file format checks that enforce close conformance to the
       class-file format specification. Developers are encouraged to use this flag when
       developing new code because the stricter checks will become the default in future
       releases.

       This option is deprecated and may be removed in a future release.

When use -Xfuture is used in launcher, output following warning message,

Warning: -Xfuture option is deprecated and may be removed in a future release.